Bidston Observatory - User contributions [en]

The Doodson-Légé Tide Predicting Machine

2024-05-17T20:06:41Z

Wave Follower: /* The Doodson-Légé Tide Prediction Machine */

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==Doodson-Légé Tide Prediction Machine==

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of £5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

[[file:Doodson-Lege_TPM.png]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.

[[File:Doodson-Lege.jpg|thumb|none|500px|The Roberts-Lege Tide Prediction Machine, that was previously in store at the Merseyside Maritime Museum, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition.]]

uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

File:Doodson-Lege.jpg

2024-05-17T20:04:37Z

Wave Follower:

[[Category: Instruments]]

This image is wrongly labelled the 'Doodson-Lege TPM', it is actually the Roberts-Lege TPM

The Doodson-Légé Tide Predicting Machine

2024-05-17T20:01:43Z

Wave Follower:

__TOC__

==The Doodson-Légé Tide Prediction Machine==

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of £5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

[[file:Doodson-Lege_TPM.png]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.

[[File:Doodson-Lege.jpg|thumb|none|500px|The Roberts-Lege Tide Prediction Machine, that was previously in store at the Merseyside Maritime Museum, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition, ]]

uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

The Doodson-Légé Tide Predicting Machine

2024-05-17T19:59:23Z

Wave Follower:

__TOC__

==The Doodson-Légé Tide Prediction Machine==

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of £5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

[[file:Doodson-Lege_TPM.png]]
<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.

[[File:Doodson-Lege.jpg|thumb|none|500px|The Roberts-Lege Tide Prediction Machine, that was previously in store at the Merseyside Maritime Museum, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition, ]]

uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

The Doodson-Légé Tide Predicting Machine

2024-05-17T19:57:11Z

Wave Follower:

__TOC__

==The Doodson-Légé Tide Prediction Machine==

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of £5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

[[file:Doodson-Lege_TPM.png]]

[[File:Doodson-Lege.jpg|thumb|none|500px|The Roberts-Lege Tide Prediction Machine, that was previously in store at the Merseyside Maritime Museum, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition, ]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

The Doodson-Légé Tide Predicting Machine

2024-05-17T19:56:18Z

Wave Follower:

__TOC__

==The Doodson-Légé Tide Prediction Machine==

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of £5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

[[file:Doodson-Lege_TPM]]

[[File:Doodson-Lege.jpg|thumb|none|500px|The Roberts-Lege Tide Prediction Machine, that was previously in store at the Merseyside Maritime Museum, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition, ]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

The Doodson-Légé Tide Predicting Machine

2024-05-17T19:54:08Z

Wave Follower:

__TOC__

==The Doodson-Légé Tide Prediction Machine==

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of £5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

[[File:Doodson-Lege.jpg|thumb|none|500px|The Roberts-Lege Tide Prediction Machine, that was previously in store at the Merseyside Maritime Museum, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition, ]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

The Doodson-Légé Tide Predicting Machine

2024-05-17T19:52:46Z

Wave Follower:

__TOC__

==The Doodson-Légé Tide Prediction Machine==

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of £5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

[[File:Doodson-Lege.jpg|thumb|none|500px|The Roberts-Lege Tide Prediction Machine, that was previously in store at the Merseyside Maritime Museum, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition, ]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

Bidston Kelvin Machine

2024-05-17T19:48:54Z

Wave Follower:

The Bidston Kelvin Machine is one of three types of Tide Predicting Machines (TPM) that have been used in the Bidston Observatory. This TPM-S14 was developed out of earlier type predicting machines, and made in 1925 by the firm of Kelvin, Bottomley and Baird of Glasgow, with Doodson taking great interest in its construction and suggesting modifications.

[[file:Bidston_Kelvin_TPM.png]]
The other types are the [[Roberts Tide Predicting Machine]] (bought in 1929) and [[The Doodson-Légé Tide Predicting Machine]] (1950).

<blockquote>"Doodson wrote in an internal note that there was no difference in performance between the Bidston Kelvin and Roberts–Légé machines. He stated that for both “the total error of production of a tide does not differ by more than 0.05 ft (1.5 cm) and 1 min of time from calculations using the same harmonic constants, even for the largest ranges of tide”.<ref>https://www.researchgate.net/publication/340064506_Tide_prediction_machines_at_the_Liverpool_Tidal_Institute#pf6</ref></blockquote>

"The Bidston Kelvin Machine may still be found at SHOM in Brest".<ref>https://www.shom.fr/</ref>

[[Category:Instruments]]

File:Bidston Kelvin TPM.png

2024-05-17T19:46:54Z

Wave Follower: Bidston Kelvin TPM used by Doodson for the tidal predictions for the D-Day landings. Now at SHOM in Brest, France

== Summary ==
Bidston Kelvin TPM used by Doodson for the tidal predictions for the D-Day landings. Now at SHOM in Brest, France

File:Doodson-Lege TPM.png

2024-05-17T19:42:00Z

Wave Follower: The Doodson-Lege Tidal Prediction machine was in use until the 1960s when digital computers became available. IIt was later exhibited in the foyer of the Proudman Building at Bidston until the Proudman Oceanographic Institute moved to the Liverpool University campus in 2004 and then stored at the Merseyside Maritime Museum in Liverpool before being refurbished in 2015 and installed at the 'Tide and Time' exhibition at the National Oceanography Centre in Liverpool.

== Summary ==
The Doodson-Lege Tidal Prediction machine was in use until the 1960s when digital computers became available. IIt was later exhibited in the foyer of the Proudman Building at Bidston until the Proudman Oceanographic Institute moved to the Liverpool University campus in 2004 and then stored at the Merseyside Maritime Museum in Liverpool before being refurbished in 2015 and installed at the 'Tide and Time' exhibition at the National Oceanography Centre in Liverpool.

The Doodson-Légé Tide Predicting Machine

2024-05-17T19:37:02Z

Wave Follower:

__TOC__

==Doodson-Légé Tide Prediction Machine==

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. The tidal predictions for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of £5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

[[File:Doodson-Lege.jpg|thumb|none|500px|The Roberts Tide Prediction Machine, that was previously in store at the Merseyside Maritime Museum, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition, ]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

The Doodson-Légé Tide Predicting Machine

2024-05-16T13:21:12Z

Wave Follower:

__TOC__

==The Doodson-Légé Tide Prediction Machine==

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of £5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

[[File:Doodson-Lege.jpg|thumb|none|500px|The Roberts Tide Prediction Machine, that was previously in store at the Merseyside Maritime Museum, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition, ]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

Temperature sensors

2024-05-16T12:29:28Z

Wave Follower:

Measuring temperature in the sea is important because this helps identify water masses and their origin. Various instruments have been developed to measure temperaure at depth inbthe ocean, including reversing mercury thermometers and more recently electronic sensors.

This picture [[File:temperature_sensors_Mk1_bottom_pressure_recorder.jpg]] shows a box of spare temerature sensors for use with the original deep sea tide gauge.

See also CTD

Temperature sensors

2024-05-16T12:28:43Z

Wave Follower: Created page with "measuring temperature in the sea is important because this helps identify water masses and their origin. Various instruments have been developed to measure temperaure at depth..."

measuring temperature in the sea is important because this helps identify water masses and their origin. Various instruments have been developed to measure temperaure at depth inbthe ocean, including reversing mercury thermometers and more recently electronic sensore.

This picture [[File:temperature_sensors_Mk1_bottom_pressure_recorder.jpg]] shows a box of spare temerature sensors for use with the original deep sea tide gauge.

File:Temperature sensors Mk1 bottom pressure recorder.jpg

2024-05-16T12:23:39Z

Wave Follower: Spare temperature sensors for the original deep sea tide gauge (Mk1)

== Summary ==
Spare temperature sensors for the original deep sea tide gauge (Mk1)

Proudman Building

2024-04-21T20:02:53Z

Wave Follower:

The Proudman Building was built in 1975 by the Natural Environment Research Council for the Institute of Oceanographic Sciences (Bidston) as it was expanding its oceanographic work.

[[File:Proudman_Building.jpg]]

See also: http://www.bidstonobservatory.org.uk/remembering-the-proudman-building/

[[Category:Sites]]

Bidston Hill

2024-04-21T19:59:21Z

Wave Follower:

* Bidston Hill is visible from afar. The Observatorium is a symbol of Liverpool's maritime heritage and colonial entanglements, connected to trading goods, slavery, the exploitation of overseas territories.
* The hill is subject of a long lineage of mystic and occult folktales.

[[File:Location.JPG|thumb|500px|view on Bidston Observatory from hillside]]

[[category:Sites]]

Atmospheric pressure sensors

2024-04-21T19:57:05Z

Wave Follower:

Atmospheric pressure sensors are meteorological instruments used to measure the atmospheric pressure

==Barograph==
This traces a graph on paper

==Barometer==
Various types exist, the most accurate contains a vertical tube of mercury which rises and falls as atmospheric pressure changes. Aneroid barometers (often household instruments) use a sealed pressure chamber.

==Surface pressure sensors for Ascension Island==
A set of 3 atmospheric pressure instruments (barograph, barometer and Digiquartz pressure sensor) were bought by Director Dr David Cartwright to make measurements at Ascension Island in the South Atlantic in 1986. Dr Cartwright initiated a programme of observations of tides in the Atlantic, using oceanic islands like Ascension and Tristan da Cunha as well as bottom pressure recorders on the sea bed. Atmospheric pressure had to be measured to correct the pressure data, to calculate sea level. The instruments have been donated by Bob Spencer, who worked closely with Dr Cartwright on these measurements.

[[Category:Instruments]]

Atmospheric pressure sensors

2024-04-21T19:55:38Z

Wave Follower:

Atmospheric pressure sensors are meteorological instruments used to measure the atmospheric pressure

==Barograph==
This traces a graph on paper

==Barometer==
Various types exist, the most accurate containing mercury. Aneroid barometers (like household instruments) use a sealed pressure chamber.

==Surface pressure sensors for Ascension Island==
A set of 3 atmospheric pressure instruments (barograph, barometer and Digiquartz pressure sensor) were bought by Director Dr David Cartwright to make measurements at Ascension Island in the South Atlantic in 1986. Dr Cartwright initiated a programme of observations of tides in the Atlantic, using oceanic islands like Ascension and Tristan da Cunha as well as bottom pressure recorders on the sea bed. Atmospheric pressure had to be measured to correct the pressure data, to calculate sea level. The instruments have been donated by Bob Spencer, who worked closely with Dr Cartwright on these measurements.

[[Category:Instruments]]

Atmospheric pressure sensors

2024-04-21T19:48:31Z

Wave Follower:

Atmospheric pressure sensors are meteorological instruments used to measure the atmospheric pressure

==Barograph==
This traces a graph on paper

==Barometer==
Various types exist, the most accurate containing mercury. Aneroid barometers (like household instruments) use a sealed pressure chamber.

==Surface pressure sensors for Ascension Island==
Three pressure

[[Category:Instruments]]

ICOT model

2024-04-21T19:42:54Z

Wave Follower:

==Architect's model of Institute of Coastal Oceanography and Tides==

When the Liverpool Tidal Institute became part of the Natural Environment Research Council (NERC) in 1969 it was renamed the Institute of Coastal Oceanography and Tides (ICOT). After rapid expansion a new building was required to house the increasing number of staff. Plans were drawn up by a firm of architects and a model of the proposed building and the Bidston site was built. This model is held in the HECS archive, but the new building, as constructed in 1975 (which became known as the Proudman Building) was not as large as that in the scale model.

[[File:ICOT_model_600x.jpeg]]

[[Category:Archives]]

ICOT model

2024-04-21T19:39:01Z

Wave Follower:

ICOT model

2024-04-21T19:37:56Z

Wave Follower: Created page with "==Architect's model of Institute of Coastal Oceanography and Tides== When the Liverpool Tidal Institute became part of the Natural Environment Research Council (NERC) in 1969..."

Proudman Building

2024-04-21T19:29:02Z

Wave Follower:

Poster Oceanographic Institute

2024-04-21T19:07:55Z

Wave Follower:

Poster detailing a brief history of oceanography at Bidston Observatory
In 1919, the Liverpool University Tidal Institute (LTI) was formed collecting some of the tide data that were used later for programming the tide-predicting machines at Bidston, after the LTI was moved to Bidston Observatory in 1929.
From the 1960's onwards, these tide prediction machines were replaced by computers.

Bidston Observatory tidal studies eventually expanded into global sea level and coastal oceanographic research, joining the Natural Environment Research Council in 1969 and later housing the British Oceanographic Data Centre (BODC)

[[category:archives]]

The Doodson-Légé Tide Predicting Machine

2024-04-21T19:00:28Z

Wave Follower:

__TOC__

==The Doodson-Légé Tide Prediction Machine==

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of GBP 5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

[[File:Doodson-Lege.jpg|thumb|none|500px|The Doodson-Légé Tide Prediction Machine that was removed from Bidston Observatory, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

The Doodson-Légé Tide Predicting Machine

2024-04-21T18:52:50Z

Wave Follower:

__TOC__

==The Doodson-Légé Tide Prediction Machine==

Having the Bidston Kelvin Machine and the Roberts Tide Prediction Machine available <blockquote>"equipped Doodson with experience that would prove invaluable when considering the design of later machines. They would also provide him with the means to enable the Liverpool Tidal Institute to become one of the main producers of tide tables worldwide. The two machines were to play particularly important roles in World War II, in providing tidal predictions for D-Day and for other military operations in Europe and the Paciﬁc. Those for D-Day were unusual in that they were made for an unknown location (now of course known to be Normandy), using only the crudest of harmonic constants provided by Commander Farquharson at the Tidal Branch of the Admiralty (Parker, 2011). However, they were not secret for long. In July 1944, Doodson gave a lengthy interview to the Liverpool Daily Post, stressing the importance of the TPMs to the D-Day predictions (LDP, 1944).

"In 1947, Doodson asked Légé to estimate the price of a machine with at least 35 components. Légé produced an initial design which Doodson started working on in detail. This became the 42-component machine delivered ﬁnally by Légé in December 1950 at a cost of GBP 5049 (Woodworth, 2016)."

"After the Bidston Kelvin Machine and the Roberts Tide Prediction Machine, the Bidston Doodson–Légé Machine (TPM-S20), which was referred to by Bidston staff as the “D–L machine”, was the third machine to be used operationally at the LTI and one of a number of similar machines made by Légé & Co. under Doodson’s supervision and exported to several countries. Doodson (1951) describes it in some detail. It was a single-sided TPM, being converted to a double-sided machine in 1956. It has an aluminium frame, unlike the steel frame of TPM-S5. The machine is approximately 7 feet (2.1 m) high, 9.5 feet (3 m) long and 3.5 feet (1.1m) wide and weighs 1.4 t (not including the support base frame). Complete engineering drawings and documentation survive which have enabled its recent restoration.7Figure 3f and g provides photographs of the machine."<ref>Tide prediction machines at the Liverpool Tidal Institute, March 2020History of Geo- and Space Sciences 11(1):15-29, DOI:10.5194/hgss-11-15-2020, Philip L. Woodworth</ref></blockquote>

<blockquote>Tidal predictions were first carried out in 1924 at Bidston Observatory (University of Liverpool Tidal Institute), initially by hand and then by early tide predicting machines.<ref>https://ntslf.org/about-tides/doodson-machine</ref></blockquote>

[[File:Doodson-Lege.jpg|thumb|none|500px|The Doodson-Légé Tide Prediction Machine that was removed from Bidston Observatory, being craned into the Joseph Proudman building at the National Oceanography Centre in Liverpool. It is now part of the Tide and Time exhibition]]

<blockquote>The Doodson-Légé tide predicting machine c.1950, probably at Bidston Observatory, Wirral second largest tide predicting machine ever built. This was a development from the earlier Roberts-Légé machine and designed by Arthur Doodson in the late 1940s and manufactured by Légé & Co. around 1948-49. This much bigger machine was “easier” to set up and, after some additional mechanism added a few years later, could calculate the high and low tide levels and their times at once - effectively halving the time it took on the older Roberts-Légé machine. It is estimated that, using the Doodson-Lége machine, it could take almost a month to calculate a year’s worth of tidal levels for a particular port and these were calculated a couple of years in advance. In comparison, it takes the computers used today a fraction of a second to do the same calculation to greater accuracy. Throughout the 1950s though, this machine was state-of-the-art. Installing the machine at the National Oceanographic Centre Installing the machine at the National Oceanographic Centre The 1.8 ton Doodson-Légé and the 1.2 ton Roberts-Légé machines were recently transported to the NOC’s Joseph Proudman Building. The process took 5 ½ hours and required a large team of people. Staff at the NOC were in a jubilant mood watching the installation and cheered as the first machine to be lifted, the Roberts-Légé machine, touched down on the pavement beside the Proudman Building. The Doodson-Légé machine is a particularly symbolic object for them as it was at the heart of their tide prediction work for international ports from c1950 to the early 1960s."
<ref>https://www.liverpoolmuseums.org.uk/stories/tide-predicting-machines-restored-and-re-displayed</ref></blockquote>

==The Portable Doodson-Légé Tide Prediction Machine==

[[File:Doodson-Lege-portable.jpg|thumb|none|500px|"Portable Doodson-Légé Tide Predictor", printed from etched copper plate in the HECS archive]]

[[File:13.2b.jpg|thumb|none|500px|HECS archive inventory nr. 13.2. Copper print plate of Portable Doodson-Légé Predicting Machine]]

Portable Tide Prediction Machine appear in inventories as 'PTPM'<ref>https://www.researchgate.net/figure/a-Inventory-of-tide-prediction-machines-b-Inventory-of-portable-tide-prediction_tbl1_340064506</ref>

[[Category:Instruments]]

Atmospheric pressure sensors

2024-04-21T18:16:15Z

Wave Follower:

Atmospheric pressure sensors are meteorological instruments used to measure the atmospheric pressure

[[Category:Instruments]]

Atmospheric pressure sensors

2024-04-21T18:12:33Z

Wave Follower:

Atmospheric pressure sensors are meteorological instruments used to measure the atmospheric pressure

Atmospheric pressure sensors

2024-04-18T17:24:57Z

Wave Follower: Created page with "Atmospheric pressure sensors are meteorological instruments used to measure the atmospheric pressure, usually at the Earth's surface"

Atmospheric pressure sensors are meteorological instruments used to measure the atmospheric pressure, usually at the Earth's surface

File:Proudman Building.jpg

2024-04-18T17:21:22Z

Wave Follower: Proudman Building built in 1975 and demolished in 2013

== Summary ==
Proudman Building built in 1975 and demolished in 2013

Proudman Building

2024-04-18T17:14:22Z

Wave Follower: Created page with "The Proudman Building was built in 1975 by the Natural Environment Research Council for the Institute of Oceanographic Sciences (Bidston) as it was expanding its oceanographic..."

File:Proudman Building Proudman Oceanographic Laboratory, Bidston Hill - geograph.org.uk - 335675.jpg

2024-04-18T17:07:57Z

Wave Follower: Tha 'new' building built in 1975, named the Proudman Building on its official opening in 1978

== Summary ==
Tha 'new' building built in 1975, named the Proudman Building on its official opening in 1978

File:ICOT model 600x.jpeg

2024-04-18T17:05:33Z

Wave Follower: The architectural model of the Institute for Coastal Oceanography and Tides (ICOT) showing the preliminary design of the proposed new building. The actual building constructed in 1875 was substantially smaller.

== Summary ==
The architectural model of the Institute for Coastal Oceanography and Tides (ICOT) showing the preliminary design of the proposed new building. The actual building constructed in 1875 was substantially smaller.

Proudman Oceanographic Laboratory

2024-04-18T17:00:25Z

Wave Follower:

The Proudman Oceanographic Laboratory (POL) was the name of the full site on which Bidston Observatory stands, enclosed by the boundary wall, including the Observatory building, the Proudman Building (built in 1975), the lighthouse and part of the Lighthouse Cottages, as well as the car park and courtyard. POL (1987-2010) was an autonomous oceanographic institute, owned and run by the Natural Environment Research Council (NERC) and became part of the National Oceanography Centre (NOC) in 2010. Previously it was known as the Institute for Coastal Oceanography and Tides (ICOT, 1969-1973) and then the Institute of Oceanographic Sciences (IOS), Bidston (1973-1987).

POL moved to the Liverpool University campus in 2004, based at 6 Brownlow Street, Liverpool, UK. The Bidston Hill site was then put up for sale and sold in 2013, after demolition of the Proudman Building. The present owners of BOARC purchased most of the site in 2016. The lighthouse and Lighthouse Cottages are now privately owned (http://www.bidstonlighthouse.org.uk/).

More on POL here: https://en.wikipedia.org/wiki/Proudman_Oceanographic_Laboratory

[[File:POL-aerial view 1986.png|400px|Aerial view of the Proudman Oceanographic Laboratory]]

<gallery mode="packed-hover">
File:POL-aerial view 1986.png|''[[Aerial view of the Proudman Oceanographic Laboratory]]''
</gallery>
[[Category:Instruments]]
[[category:Sites]]

Proudman Oceanographic Laboratory

2024-04-18T16:58:38Z

Wave Follower:

The Proudman Oceanographic Laboratory (POL) was the name of the full site on which Bidston Observatory stands, enclosed by the boundary wall, including the Observatory building, the Proudman Building (built in 1975), the lighthouse and part of the Lighthouse Cottages, as well as the car park and courtyard. POL (1987-2010) was an autonomous oceanographic institute, owned and run by the Natural Environment Research Council (NERC) and became part of the National Oceanography Centre (NOC) in 2010. Previously it was known as the Institute for Coastal Oceanography and Tides (ICOT, 1969-1973) and then the Institute of Oceanographic Sciences, Bidston (1973-1987).

POL moved to the Liverpool University campus in 2004, based at 6 Brownlow Street, Liverpool, UK. The Bidston Hill site was then put up for sale and sold in 2013, after demolition of the Proudman Building. The present owners of BOARC purchased most of the site in 2016. The lighthouse and Lighthouse Cottages are now privately owned (http://www.bidstonlighthouse.org.uk/).

More on POL here: https://en.wikipedia.org/wiki/Proudman_Oceanographic_Laboratory

[[File:POL-aerial view 1986.png|400px|Aerial view of the Proudman Oceanographic Laboratory]]

<gallery mode="packed-hover">
File:POL-aerial view 1986.png|''[[Aerial view of the Proudman Oceanographic Laboratory]]''
</gallery>
[[Category:Instruments]]
[[category:Sites]]

File:POL-aerial view 1986.png

2024-04-18T16:55:18Z

Wave Follower: Aerial image of the Institute of Oceanographic Sciences (Bidston), later named the Proudman Oceanographic Laboratory, taken in 1986. Note thee domes had been painted black for economic reasons, they were white initially and subsequently to keep the domes cool.

== Summary ==
Aerial image of the Institute of Oceanographic Sciences (Bidston), later named the Proudman Oceanographic Laboratory, taken in 1986. Note thee domes had been painted black for economic reasons, they were white initially and subsequently to keep the domes cool.

IBM 1130

2024-04-18T16:49:54Z

Wave Follower:

In 1969, an [https://lh3.googleusercontent.com/proxy/uL7IH396jqNXVsR3G65U3KxXSwqm-XBZawU2FgkjqoMLUE8-x25LrNCRhaYReClDkrOb50mK-UNTrmr7CYq_X34EQ0CDy8EyA30eDBE6Hgs IBM 1130] computer was installed in the basement of Bidston Observatory, connected to an IBM 360 at the London Data Centre. Prior to this, scientists still had to send off their computational work to Liverpool University or later to the Daresbury Laboratory in Cheshire. Oceanographers at the time started to use this machine to model coastal and shelf seas, including development of the storm surge prediction model by Norman Heaps and Roger Flather.

On how the capacities of processing define the measurement:

Astronomers have long measured the passage of time using Julian dates, defined by Joseph Scaliger in 1853 as the number of days that have passed since noon on January 1, 4713 BC. In 1957, the Smithsonian Astrophysical Union wanted to track Sputnik using a 36-bit IBM 704 computer. They needed 18 bits to store the time down to 100 nanoseconds. The day had to fit in the remaining 18 bits, so they tracked a Modified Julian Date, defined as the days since midnight of November 17, 1858 (Julian day 2,400,000.5).

[[category:instruments]]

IBM 1130

2024-04-18T12:51:01Z

Wave Follower:

In 1969, an [https://lh3.googleusercontent.com/proxy/uL7IH396jqNXVsR3G65U3KxXSwqm-XBZawU2FgkjqoMLUE8-x25LrNCRhaYReClDkrOb50mK-UNTrmr7CYq_X34EQ0CDy8EyA30eDBE6Hgs IBM 1130] computer was installed in the basement of Bidston Observatory, connected to an IBM 360 at the London Data Centre. This was relatively late - prior to this, data scientists still had to send off the charts to an organisation in Cheshire. Oceanographers at the time used this machine to model coastal & shelf seas.

On how the capacities of processing define the measurement:

Astronomers have long measured the passage of time using Julian dates, defined by Joseph Scaliger in 1853 as the number of days that have passed since noon on January 1, 4713 BC. In 1957, the Smithsonian Astrophysical Union wanted to track Sputnik using a 36-bit IBM 704 computer. They needed 18 bits to store the time down to 100 nanoseconds. The day had to fit in the remaining 18 bits, so they tracked a Modified Julian Date, defined as the days since midnight of November 17, 1858 (Julian day 2,400,000.5).

[[category:instruments]]

Proudman Oceanographic Laboratory

2024-04-18T12:33:34Z

Wave Follower:

The Proudman Oceanographic Laboratory (POL) was the name of the full site on which Bidston Observatory stands, enclosed by the boundary wall, including the Observatory building, the Proudman Building (built in 1975), the lighthouse and part of the Lighthouse Cottages, as well as the car park and courtyard. POL (1987-2010) was an autonomous oceanographic institute, owned and run by the Natural Environment Research Council (NERC) and became part of the National Oceanography Centre (NOC) in 2010. Previously it was known as the Institute for Coastal Oceanography and Tides (ICOT, 1969-1973) and then the Institute of Oceanographic Sciences, Bidston (1973-1987).

POL moved to the Liverpool University campus in 2004, based at 6 Brownlow Street, Liverpool, UK. The Bidston Hill site was then put up for sale and sold in 2013, after demolition of the Proudman Building. The present owners of BOARC purchased most of the site in 2016. The lighthouse and Lighthouse Cottages are now privately owned (http://www.bidstonlighthouse.org.uk/).

More on POL here: https://en.wikipedia.org/wiki/Proudman_Oceanographic_Laboratory

[[File:Proudman Oceanographic Laboratory model.jpeg|400px|Architectural model of the Proudman Oceanographic Laboratory, in the HECS archive]]

<gallery mode="packed-hover">
File:Proudman Oceanographic Laboratory model.jpeg|''[[Architectural model of the Proudman Oceanographic Laboratory, in the HECS archive]]''
</gallery>
[[Category:Instruments]]
[[category:Sites]]

About HECS

2024-04-18T11:44:07Z

Wave Follower: /* Orientations of the HECS */

<div class="box">'''The Heritage Education Centre Space (HECS) is dedicated to critically exploring the history of the Bidston Observatory'''</div>

== The Heritage Education Centre Space is Open / HECS is ajar! ==

This wiki is a space for testing out ideas for the Heritage Education Centre Space (HECS) that is unfolding. HECS is not quite yet open, so we use: ajar. Open means: open for construction. Open for contributions, participation. Ajar means: there will be some effort and energy involved to open up the space, we welcome and are grateful for the involvement, and the parameters of this are not yet fixed.

Also, "HECS" phonically invokes what has been historicized as outside of science, motions towards folkloric & pagan practices (hex). Take this as a spell:

=== Orientations of the HECS ===

Bidston Observatory is situated on the Wirral peninsula, in the UK. It is currently occupied by [https://bidstonobservatory.org Bidston Observatory Artistic Research Centre] (BOARC).

As part of BOARC’s wider project, the Heritage Education Centre (HECS) is dedicated to critically exploring the history of the building, the surrounding area, and the global networks of transit, exploration and extraction made possible by science in the British Empire.

Bidston's imbrication in the history of maritime trade and the British Empire calls for dedicated research into the ethical, contextual and expanded forms of visual culture, and museum and curatorial practice, which would support these histories.

HECS looks to engage in the complexity of visual cultures necessary to address the critical enquiry into nineteenth century British history. Part of HECS’ remit is to ask questions such as: How can a local museum reflect contemporary post-colonial discourse at the intersection of art and science? And: How might it be possible to situate this dialogue within scholarly and museological debate, at the same time as responding to this location and demand from communities which surround it?

The HECS documents spaces, objects and instruments related to Bidston Observatory - however these relations can be thought along networked, distributed or expanded forms. Most of the usual tales being told and retold about the national monuments, including this observatory, celebrate a succession of White British Male scientists and their great inventions. HECS tries to make space for accounts that are extra to nation state, hetero-normative ideas of progress and the advancement of science.

The practice of observation, operating scientific instruments and investment in observatories is entangled with different scales of capitalist endeavour, colonialist and imperialist modes of worlding. The Bidston Observatory is connected to such modes through its contributions to the maritime industry, natural earth sciences and oceanography. HECS interrogates different instrumentations and approaches in these historically defined disciplines at various scales. It is a place to articulate these connections, and the responsibilities they bring.

HECS gathers facts about the building itself, the artefacts and instruments that it once housed and still houses, but tries to connect them to larger histories and futures. No histories are told without bias, and so are the stories in this wiki.

== Why/what/where/when/how HECS? ==

=== H as in Heritage and... ===

patrimony and as in inheritance and as in unexpected modes of passing on. We have learned from our ancestors and predecessors (of social constructivism in STS, of situated knowledges in feminist technosciences, of self-management in the DIY scenes accross the globe, from anti-repression and anti-colonial struggle organisation) how to critique and problematise the so-called Modern Project and its systems of values from the very tissue of it, but we try to use our imbrication to develop generative and reparative strategies. Through the H in HECS we understand heritage not as that which may be inherited, codified in ways that determine what counts as valuable or recessive (in a gradient of violent pedigree) and gets smoothly transferred. We rather try to engage with heritage as a praxis of response-ability, solidarity, friction and open-ended (sometimes even chain-breaking) critique within different communities of practice (Isabelle Stengers), acknowledging that each of them at their particular times need to transfer knowledge and modes of doing, but not necessarily following pre-set conditions for how values, notions, manners or tools get passed along. The passing along implies an intersectional unserstandings of inter-dependent generations, disciplines, positionalities and degrees of expertise.

What would a praxis of heritage based on trans*ness operate like? The star (*) in trans* asks for a moment to consider which elements are more significantly intersected for each specific community of practice. Is it the labour conditions? Is it the gender assumptions and assignations? Is it age, ability, academic legitimacy, origin, language, beliefs, systematizations, opressions, species?

Due to the historical damages inflicted over bodies and communities by means of normative inheritance systems, at HECS we are commited to an active and ongoing calibration of investment, value and pertenence based on an accountability on our own terms, of course revisable and necessarily unfinished. In other words: just because you are "in the family" that does not give you immediately the right to own properties, to reproduce biases or to repeat manners. Passing along a pre-set of lineage with its correspondant component of genetic inheritance, property ownership or incapacity and elitism or exclusion --depending on the position of privilege or surrogatedness of such lineage-- is what we try to actively crook. But crooking is not erasing, and hence we are committed to a reformulation of heritage by other means, more attuned to complex forms of transmission and needed forms of making processes otherwise.

Heritage for the HECS is considered to revolve around non-original objects, or around material and inmaterial objects (of study?) which do not always have patrimonistic lineages and certainly should not have naturalized paths into our lives. Such objects can be loosely connected to situatedness. Objects in HECS are not examples of what was originally used in Bidston Observatory, to start with. They are perhaps objects of chosen traced histories (understanding that the telling of History is also the result of a choice, a never-neutral nor innocent choice), and the result of expanding the lines traced in surprising directions for the flourishing of other worldy formations, as cosmic or mundane as they might need to be.

Heritage also takes an active stake on the many (and often deeply contradictory) legacies of discovery, observation, findings, stabilizing and settlement paradigms, scientific labour or mandatory progress by means of development. As a non-natural, non-familiar transmission, queer, anti-colonial and trans* heritage here is inhabited as both the knowledge and forms of knowledges passed on, never singular, never unidirectional, and so our understanding of heritage in the HECS must be reflective of inter-dependent multiplicities. It is a heritage that needs to be based on a collective and mutant exploration of difference without separability (Da Silva).

So we take the task to, on a daily basis, find ways of speaking, addressing, observing, unnaming and being together to pass knowledge to each other, and to others.

Also, there is a catagory called "stories" on this wiki dedicated to stories which might be useful to thicken the notion of history without a withdrawal of response-ability.: https://wiki.bidstonobservatory.org/index.php/Category:Stories

Other elements to speak about inheritance could include: situatedness of social constructuvism, the contemporary legitimacy of speculation, the importance of orality in technoscientific transmission of a multiplicity of heritage, and so on and so forth.

=== E as in Education or... ===

... experiments - in communal/convivial study, learning, co-enquiry and research. Understanding education as the passing on of knowledge within a system, which oftentimes has levels of hierarchy. Education's roots can be traced to (re)inventions in benevolence, discipline and labour. In the activities of HECS, we wish to create study space which welcomes many forms of knowledge, radical attention, genuine curiosity and openness for unlearning some bits and pieces of coercive knowledge formations. Not only between individuals or communities, but also affecting structures as bigger agents (institutions, funding bodies, disciplinar fields as a whole) with the potential to learn, themselves, in active and proactive manners.

... or appreciation and respect - for the the ways that this site is cherished by different people.

... or mutual care and respect for differences in sensibilities, urgencies, triggers or interests.

... or co-habitation - with the other lifeforms onsite, with the previous work done here, with complex and multiple stories of nature-cultures, science research and popular wisdom -- for example in relation to the neighbor lighthouse, or the hill informal economies, or the landscape mutations along generations.

... or a shared field of study which we aim to make accessible in different ways, to enable different people to engage with the notion of "community of practice".

... or the many differences found along learning and knowledge circulation, unlearning processes, etc.

...or not being only reactive to theoretical trends and attuning often to smaller and more experimental zones of understanding to
slow down an approach to the thick complexities of the mundane in generative, not so much reactive-to agenda-based waves of interest. Looking at the legacy of Science and technological progress, in terms of both 'who benefits' and 'who is harmed', and understanding that this cannot be divorced from the application of the technology. Raising awareness about the intersection between science and politics, through making connections. Exploring the historical, political and cultural relations that co-constitute objects/artifacts/instruments in the HECS. Knowledge making and sharing involve multiple practices and have many different formats of outcome, not just academic papers.

...or learning experiments with as many teachers as it has participants. It is motivated by the possibility to displace parameters of/for research, studying and learning, informed by companion experiences like the Relearn Summerschool (http://relearn.be). The HECS welcomes persons from all backgrounds and disciplines, who can be willing to engage with the histories . From relearn citation:
"Participants will gather to learn from and teach to each other, beyond the traditional paradigms of education. Relearn researches convivial, experimental and deviant methods and means in the fields of design, computing and education, challenging the normal roles and separations in them"

... or trying with as many tools as we could re-imagine: wiki/FLOSS, radio!, stays, collective cooking/gardening/...

=== C as in Centre despite... ===

... our intention to displace the object from the main focus. In the HECS, we understand knowledge to be co-constituted and partial. We tell multiple and divergent accounts of the histories which intersect at the site. Some of these histories are the more well-trodden contributions to British maritime trade and natural earth sciences. Some are lesser known, or expanded in surprising ways. The HECS doesn't centralise an authorial museum 'voice', but rather aims to include a diversity of accounts, told by different human and non-human actors.

...despite a displacement of the subject from the center of our attentions does not mean the displacement of the subject's response-abilities

...despite understanding center as a spot of rigid coordinates, unmovable and static, we say Center to mean a place to return to after fun, complicated, significant and tricky drifts. Not so much centre as a place to not get out from, but as a zone to try and converge back. A center as a place to return to a grounding in materiality, and zone of consensuated stability used more to stay active than to stay upright. A center as an axis to tilt, twist and recursively come back to, but transformed.

...despite the need for a location or point of focus. Of course, such focus is necesarily revisable, but we need to be aware of what our consensuated center is (a least common multiple that will necessarily vary along time, changed by our very practices).

...despite Museums are typically still rooted in the very center of nineteenth century thought, operating as public spaces for educational emancipation, and supporting canonical versions of histories which have, at root, accumulative principles and classist or colonial mind-sets. Currently, such museology is under heavy scrutiny, and collecting as a practice of accumulation is being questioned deeply; so too is the function of museums as gatekeepers of value. As we begin HECS in this moment of criticality - which many of us have worked to raise - we also look towards reimagining the visual cultures which have supported the colonial and modern projects.

...despite we are trying to rethink the well-established tradition of display, so specific for science and technology museums. As the HECS sits within a research site (BOARC), it's slow aims are to engage audiences in a way that negotiates the accepted and to-be- expected scenography, relevant and open to divergent audiences, while provoking an informed reflection on histories of Western modernity. On this research site, which is neither museum nor education centre, but host to a vibrant community of invested research practitioners, there is potential for a sensitive, experimental curatorial approach, which combines a critical reflection on the culture of observation with a thorough rethinking of the implications of local museum display.

=== S as in Space but... ===

... the words 'Centre' & 'Space' are placed together, to signify a displacement of a central object, an empty middle that expelled the traditionally centered elements of both subject and object, and transports them into eccentric spaces, inner, outer, other.

... but also as in "giving space" to ourselves as well as "leaving space" for others, assuming the amount of accumulated privileges and oppresions often magnetizing around our very modes of existance and the categories imposed upon them.

... but spaced in constant evacuation/eviction, with a tending-to-void middle. We understand this as non-accumulative practices, time-poor practices,

...but while national museums face the challenge of examining their collections and display, local museums such as HECS, can work in a more deft manner. HECS tries to maintain an expansive focus rather than concentrating on one central underpinning 'H'istory. This brings questions of permeability, permanence, reification, nostalgia and more.

...but HECS also works with absences, removed instruments and traces. It doesn't look to conserve in the traditional sense, but to take different approaches to the relation of heritage and preservation. Some of these are: hearing the silences of erased oral histories of technosciences, taking the partial and non-innocent position of "guardians" of Bidston Observatory, practicing palliative care for a world that needs to die (and will do), leaving be and being ok with the now!

=== Questions ===

These are some of the questions that came up while we are trying to imagine to build the HECS in discussion with many others. Please feel welcome to add questions, or to rephrase the ones below.

* How to contextualise The Bidston Observatory? As a colonial apparatus, as ...
* How can our understandings of the site and its histories not reproduce colonial relationships and patterns?
* Are the instruments at the site usuable, dead, or a mix of both? How can their active use and application be a part of artistic research in the present?
* How do the instruments at Bidston today relate to replicas, originals or other versions of the same technologies?
* How can damage to the site and related objects be rethought? What repair skills – conceptual and mechanical – can contributors bring?
* What ways of thinking or practices could be hospiced into disappearance rather than repaired?
* What does it mean to accumulate a collection, in a site like this? For a project like BOARC?
* What defines a museum? What counts as heritage?
* Can this wiki document the absences and traces at Bidston Observatory?
* How does the space of Bidston reflect its intended uses? How can Bidston and its 'contents' be repurposed?
* How can the wiki include views from different people impacted by colonialism and its legacies? By disgruntled historians of science, astronomy, and oceanography? By the local community?
* Can the entries here archive aspects of how knowledge has been made and structured, now and in the past?
* How can the wiki address archival sources in ways that read them both against and along the grain of their original purposes?
* How is instrumentation linked to slavery?
* How to take the wider implications of observation into account?

Sextant

2024-02-09T16:27:33Z

Wave Follower:

Also known as the '''W Gerrard 19C Brass Sextant'''

<blockquote>A 19th Century Brass Sextant, with Ebonised Handle, stamped to the frame. Made by W Gerrard, Liverpool

This is a typical sextant, which would have been used by ships’ captains and deck officers for navigation by shipping companies operating out of Liverpool.

There is also a modern plastic Davis Mk 3 seextant, along with its manual, which can be used to demonstrate the principles of taking a sight for navigation. </blockquote>

[[File:Brass_and_Plastic_sextant.jpg|400px|Physical artefacts belonging to HECS]]

[[Category:Instruments]]

CTD monitor

2024-02-09T16:24:16Z

Wave Follower: /* Aquapack CTD profiler */

Also known as '''CTD profiler'''
This page attempts to trace a line between history of the CTD profiling instrument, including non-human useage.

== Aquapack CTD profiler==

A CTD profiler measures the vertical profile of conductivity, temperature and depth through the water column, providing measurements of temperature and salinity, which characterise the water masses in the ocean. This instrument was donated to the HECS by the Brotish Antarctice Survey in July 2023, now being surplus to requirements. It had been used for the early part of the sustained year-round oceanographic measurements from Rothera Research Station, Antarctica, 1997–2017. The Aquapack was made by Chelsea Instruments and rated to 200m.

[[File:Aquapack CTD deployment.jpg|400px|The Aquapack CTD is on display in the HECS]]

== CTD profile==

Picture a column, starting at the surface of the ocean and descending to the ocean floor. Conceptualised by the discipline of oceanography, this is the area delineated for measuring qualities of water, an architecture of modernity.

This logic follows the long history of the way that the seascape has been imagined by different disciplines of Western science. CTD instruments which now rise through these vertical delineations, are preceded by hemp ropes, weighted with lead, which would be dropped from the side of a ship. As the rope dropped, it ran through the hands of the sailors. Knots on the rope, representing fathoms, were called out, and marked down with a quill pen.

== Sounding line ==

“I have been asked by the Captain to try to explain to you as well as I am able, what is the object of our expedition & what we are doing from day to day. I need not remark that it gives me pleasure to do so, for we are to be common shipmates for the next few years & doubtless each one has some interest in the work, the results, if successful, will be creditable to us all. In the first place I must tell you that the bottom of the sea occupies an area of the globe, & this immense portion has been a sealed book to the human race. We have a comparatively accurate notion of the land; we know the geology and the Natural History of much of the countries of the earth, even Africa and Australia are becoming annually more known to us; and the indomitable energy of man is slowly but surely bringing each country into what I may call the regular routine, & causing it to contribute somewhat to the comfort & happiness of the rest; inasmuch as their productions whether natural or artificial, whether as necessary or more generally as (luxuries) are spread in this manner over the world, & in this way conduces to the general happiness of mankind. One reason why our ancestors did nothing towards lifting the soil from the sea bottom was because it was thought that no object could be gained by so doing; and the difficulties in the way were deemed insurmountable. For it was thought, and with reason, that nothing living could exist at a greater depth than about 400 fathoms. Now you all know that when an empty bucket is put over the ships side & allowed to sink down a little distance, what difficulty there is in hauling it up, & what a resistance is offered by the weight of water on the top of it. That resistance increases the lower we go; so that if a man was placed at the bottom...<ref> Lecture by Thompson to crew of Challenger, 1873
Substance of Professor Wyville Thompson's Lecture, to the ship's company of H.M. Ship, Challenger, on the Geography of the sea & the object of the challenger expedition. With remarks on the progress hitherto made.
Collection: Scripps Institution of Oceanography Letters, Clippings, Ships' Logs
</ref>”

== Wildlife oceanographers ==

This is a seal which has been fitted with a CTD sensor.
[[File:Meop seal2-640x426.jpg |500px]]

"The average seal dive profiled by the CTDs went to a depth of 500 meters, with some reaching 2,000 meters. The fist-sized instruments, which are glued to a seal’s head and transmit data when it surfaces from a dive, last for about five months before running out of power. Seals molt each year, shedding the instruments along with their fur.

In order to make this cache of data useful, the researchers put the profiles through extensive quality control and calibration. What comes out the other end is just about as good as the Argo data. To see what this gets us, the researchers used a model that takes in available observations and simulates the global ocean circulation pattern that fits them best. This was done for an 18-month period using only the Argo data, and then again using the seal data as well. The two were then compared to see the difference made by the seal data—showing what we would otherwise miss, in other words.

Including the seal data tended to decrease the temperatures estimated for surface water near Antarctica and increase those farther from shore. Salinity increased markedly to the west of the Antarctic Peninsula and lowered a bit elsewhere.

Some of the most interesting differences relate to sea ice behavior. When seawater freezes, salt is excluded from the crystallizing ice. That makes the remaining seawater saltier and, therefore, more dense. The data collected by the seals showed this being more pronounced, affecting surface water circulation. The sea ice itself was also better estimated by the seal-assisted model, with the output comparing more favorably with satellite observations."

Edit?
https://arstechnica.com/science/2013/12/seals-lend-scientists-a-helping-flipper-in-the-southern-ocean/

[[File:Wildlife computers elephant seal ctd.png]]
<br/>
Figure 2—The track of a southern elephant seal tagged with a prototype SCOUT-CTD tag at Península Valdés. The seal migrated east over the course of a month into an area with high salinity, warm-core eddy formed by the Brazil Current before turning back toward the coast. The SST image is from the midpoint of the migration. While temperatures warmed over the two-month period, warmer, low-salinity water near the coast, the northward cold-water current in the center, and warmer high-salinity water offshore were persistent throughout the track. Colored triangles on the map indicate the locations corresponding to the profiles in the right panels.
Suzy Kohin
https://wildlifecomputers.com/blog/promising-field-trial-results-prototype-scout-ctd-tags-transmit-thousands-of-temperature-and-salinity-profiles/

[[category: Instruments]]

File:Aquapack CTD deployment.jpg

2024-02-09T16:20:30Z

Wave Follower:

CTD monitor

2024-02-09T16:18:40Z

Wave Follower:

Also known as '''CTD profiler'''
This page attempts to trace a line between history of the CTD profiling instrument, including non-human useage.

== Aquapack CTD profiler==

This instrument was donated to the HECS by the Brotish Antarctice Survey in July 2023, now being surplus to requirements. It had been used for the early part of the sustained year-round oceanographic measurements from Rothera Research Station, Antarctica, 1997–2017. The Aquapack was made by Chelsea Instruments and rated to 200m.

[[File:Aquapack CTD deployment.jpg|400px|The Aquapack CTD is on display in the HECS]]

== CTD profile==

Picture a column, starting at the surface of the ocean and descending to the ocean floor. Conceptualised by the discipline of oceanography, this is the area delineated for measuring qualities of water, an architecture of modernity.

This logic follows the long history of the way that the seascape has been imagined by different disciplines of Western science. CTD instruments which now rise through these vertical delineations, are preceded by hemp ropes, weighted with lead, which would be dropped from the side of a ship. As the rope dropped, it ran through the hands of the sailors. Knots on the rope, representing fathoms, were called out, and marked down with a quill pen.

== Sounding line ==

“I have been asked by the Captain to try to explain to you as well as I am able, what is the object of our expedition & what we are doing from day to day. I need not remark that it gives me pleasure to do so, for we are to be common shipmates for the next few years & doubtless each one has some interest in the work, the results, if successful, will be creditable to us all. In the first place I must tell you that the bottom of the sea occupies an area of the globe, & this immense portion has been a sealed book to the human race. We have a comparatively accurate notion of the land; we know the geology and the Natural History of much of the countries of the earth, even Africa and Australia are becoming annually more known to us; and the indomitable energy of man is slowly but surely bringing each country into what I may call the regular routine, & causing it to contribute somewhat to the comfort & happiness of the rest; inasmuch as their productions whether natural or artificial, whether as necessary or more generally as (luxuries) are spread in this manner over the world, & in this way conduces to the general happiness of mankind. One reason why our ancestors did nothing towards lifting the soil from the sea bottom was because it was thought that no object could be gained by so doing; and the difficulties in the way were deemed insurmountable. For it was thought, and with reason, that nothing living could exist at a greater depth than about 400 fathoms. Now you all know that when an empty bucket is put over the ships side & allowed to sink down a little distance, what difficulty there is in hauling it up, & what a resistance is offered by the weight of water on the top of it. That resistance increases the lower we go; so that if a man was placed at the bottom...<ref> Lecture by Thompson to crew of Challenger, 1873
Substance of Professor Wyville Thompson's Lecture, to the ship's company of H.M. Ship, Challenger, on the Geography of the sea & the object of the challenger expedition. With remarks on the progress hitherto made.
Collection: Scripps Institution of Oceanography Letters, Clippings, Ships' Logs
</ref>”

== Wildlife oceanographers ==

This is a seal which has been fitted with a CTD sensor.
[[File:Meop seal2-640x426.jpg |500px]]

"The average seal dive profiled by the CTDs went to a depth of 500 meters, with some reaching 2,000 meters. The fist-sized instruments, which are glued to a seal’s head and transmit data when it surfaces from a dive, last for about five months before running out of power. Seals molt each year, shedding the instruments along with their fur.

In order to make this cache of data useful, the researchers put the profiles through extensive quality control and calibration. What comes out the other end is just about as good as the Argo data. To see what this gets us, the researchers used a model that takes in available observations and simulates the global ocean circulation pattern that fits them best. This was done for an 18-month period using only the Argo data, and then again using the seal data as well. The two were then compared to see the difference made by the seal data—showing what we would otherwise miss, in other words.

Including the seal data tended to decrease the temperatures estimated for surface water near Antarctica and increase those farther from shore. Salinity increased markedly to the west of the Antarctic Peninsula and lowered a bit elsewhere.

Some of the most interesting differences relate to sea ice behavior. When seawater freezes, salt is excluded from the crystallizing ice. That makes the remaining seawater saltier and, therefore, more dense. The data collected by the seals showed this being more pronounced, affecting surface water circulation. The sea ice itself was also better estimated by the seal-assisted model, with the output comparing more favorably with satellite observations."

Edit?
https://arstechnica.com/science/2013/12/seals-lend-scientists-a-helping-flipper-in-the-southern-ocean/

[[File:Wildlife computers elephant seal ctd.png]]
<br/>
Figure 2—The track of a southern elephant seal tagged with a prototype SCOUT-CTD tag at Península Valdés. The seal migrated east over the course of a month into an area with high salinity, warm-core eddy formed by the Brazil Current before turning back toward the coast. The SST image is from the midpoint of the migration. While temperatures warmed over the two-month period, warmer, low-salinity water near the coast, the northward cold-water current in the center, and warmer high-salinity water offshore were persistent throughout the track. Colored triangles on the map indicate the locations corresponding to the profiles in the right panels.
Suzy Kohin
https://wildlifecomputers.com/blog/promising-field-trial-results-prototype-scout-ctd-tags-transmit-thousands-of-temperature-and-salinity-profiles/

[[category: Instruments]]

CTD monitor

2024-02-09T15:49:50Z

Wave Follower: /* CTD */

This page attempts to trace a line between history of the CTD, non-human useage? edit

== CTD profile==

Picture a column, starting at the surface of the ocean and descending to the ocean floor. Conceptualised by the discipline of oceanography, this is the area delineated for measuring qualities of water, an architecture of modernity.

This logic follows long history of the way that the seascape has been imagined by different disciplines of Western science. CTD instruments which now rise through these vertical delineations, are preceded by hemp ropes, weighted with lead, which would be dropped from the side of a ship. As the rope dropped, it ran through the hands of the sailors. Knots on the rope, representing fathoms, were called out, and marked down with a quill pen.

== Sounding line ==

“I have been asked by the Captain to try to explain to you as well as I am able, what is the object of our expedition & what we are doing from day to day. I need not remark that it gives me pleasure to do so, for we are to be common shipmates for the next few years & doubtless each one has some interest in the work, the results, if successful, will be creditable to us all. In the first place I must tell you that the bottom of the sea occupies an area of the globe, & this immense portion has been a sealed book to the human race. We have a comparatively accurate notion of the land; we know the geology and the Natural History of much of the countries of the earth, even Africa and Australia are becoming annually more known to us; and the indomitable energy of man is slowly but surely bringing each country into what I may call the regular routine, & causing it to contribute somewhat to the comfort & happiness of the rest; inasmuch as their productions whether natural or artificial, whether as necessary or more generally as (luxuries) are spread in this manner over the world, & in this way conduces to the general happiness of mankind. One reason why our ancestors did nothing towards lifting the soil from the sea bottom was because it was thought that no object could be gained by so doing; and the difficulties in the way were deemed insurmountable. For it was thought, and with reason, that nothing living could exist at a greater depth than about 400 fathoms. Now you all know that when an empty bucket is put over the ships side & allowed to sink down a little distance, what difficulty there is in hauling it up, & what a resistance is offered by the weight of water on the top of it. That resistance increases the lower we go; so that if a man was placed at the bottom...”

== Wildlife computers ==

[[File:Meop seal2-640x426.jpg |500px]]

"The average seal dive profiled by the CTDs went to a depth of 500 meters, with some reaching 2,000 meters. The fist-sized instruments, which are glued to a seal’s head and transmit data when it surfaces from a dive, last for about five months before running out of power. Seals molt each year, shedding the instruments along with their fur.

In order to make this cache of data useful, the researchers put the profiles through extensive quality control and calibration. What comes out the other end is just about as good as the Argo data. To see what this gets us, the researchers used a model that takes in available observations and simulates the global ocean circulation pattern that fits them best. This was done for an 18-month period using only the Argo data, and then again using the seal data as well. The two were then compared to see the difference made by the seal data—showing what we would otherwise miss, in other words.

Including the seal data tended to decrease the temperatures estimated for surface water near Antarctica and increase those farther from shore. Salinity increased markedly to the west of the Antarctic Peninsula and lowered a bit elsewhere.

Some of the most interesting differences relate to sea ice behavior. When seawater freezes, salt is excluded from the crystallizing ice. That makes the remaining seawater saltier and, therefore, more dense. The data collected by the seals showed this being more pronounced, affecting surface water circulation. The sea ice itself was also better estimated by the seal-assisted model, with the output comparing more favorably with satellite observations."

Edit?
https://arstechnica.com/science/2013/12/seals-lend-scientists-a-helping-flipper-in-the-southern-ocean/

[[File:Wildlife computers elephant seal ctd.png]]
<br/>
Figure 2—The track of a southern elephant seal tagged with a prototype SCOUT-CTD tag at Península Valdés. The seal migrated east over the course of a month into an area with high salinity, warm-core eddy formed by the Brazil Current before turning back toward the coast. The SST image is from the midpoint of the migration. While temperatures warmed over the two-month period, warmer, low-salinity water near the coast, the northward cold-water current in the center, and warmer high-salinity water offshore were persistent throughout the track. Colored triangles on the map indicate the locations corresponding to the profiles in the right panels.
Suzy Kohin
https://wildlifecomputers.com/blog/promising-field-trial-results-prototype-scout-ctd-tags-transmit-thousands-of-temperature-and-salinity-profiles/

Lecture by Thompson to crew of Challenger, 1873
Substance of Professor Wyville Thompson's Lecture, to the ship's company of H.M. Ship, Challenger, on the Geography of the sea & the object of the challenger expedition. With remarks on the progress hitherto made.
Collection: Scripps Institution of Oceanography Letters, Clippings, Ships' Logs

[[category: Instruments]]

Chronometer

2024-02-09T15:42:43Z

Wave Follower:

Also known as '''Marine Chronometer'''

<blockquote>This is an example of a marine chronometer, made by Victor Kullberg, which is in the Royal Museums Greenwich. Marine chronometers were used to keep accurate Greenwich mean time at sea. In conjunction with a sextant to observe local noon time, this allowed the determination of longitude (defined relative to the zero longitude at Greenwich).

During the latter part of the 19th century, ships' chronometers would have been brought to Bidston Observatory for setting accurate Greenwich Mean Time and rating. Rating included checking the temperature response of the chronometer using the 'hotbox' developed by the Obsevatory's Director John Hartnup.
<ref>Bidston Observatory, the Place and the People. Joyce Scoffield. Countyvise limited. 2006</ref></blockquote>

[[File:Victor Kullberg marine chronometer - Royal Museums Greenwich.jpg|400px|Victor Kullberg marine chronometer displayed in Royal Museums Greenwich]]

[[Category:Instruments]]

Chronometer

2024-02-09T15:41:27Z

Wave Follower:

Also known as '''Marine Chronometer'''

<blockquote>This is an example of a marine chronometer, made by Victor Kullberg, which is in the Royal Museums Greenwich. Marine chronometers were used to keep accurate Greenwich mean time at sea. In conjunction with a sextant to observe local noon time, this allowed the determination of longitude (defined relative to the zero longitude at Greenwich.

During the latter part of the 19th century, ships' chronometers would have been brought to Bidston Observatory for setting accurate Greenwich Mean Time and rating. Rating included checking the temperature response of the chronometer using the 'hotbox' developed by the Obsevatory's Director John Hartnup.
<ref>Bidston Observatory, the Place and the People. Joyce Scoffield. Countyvise limited. 2006</ref></blockquote>

[[File:Victor Kullberg marine chronometer - Royal Museums Greenwich.jpg|400px|Victor Kullberg marine chronometer displayed in Royal Museums Greenwich]]

[[Category:Instruments]]

Chronometer

2024-02-09T15:35:54Z

Wave Follower:

Also known as '''Marine Chronometer'''

<blockquote>During the latter part of the 19th century, ships' chronometers would have been brought to Bidston Observatory for setting accurate Greenwich Mean Time and rating. Rating included checking the temperature response of the chronometer using the 'hotbox' developed by the Obsevatory's Director John Hartnup.</blockquote>

[[File:Victor Kullberg marine chronometer - Royal Museums Greenwich.jpg|400px|Victor Kullberg marine chronometer displayed in Royal Museums Greenwich]]

[[Category:Instruments]]