Reference numberDM/4
TitleDomestic Manuscripts Volume 4
DescriptionNos 1-45 Letters and Documents relating to General Roy's Survey & Triangulation across the Channel, 1783-1795
Papers on British and French co-operation on Triangulation date from 1783-1787. The papers on the triangulation of the British Isles dates from the 1790s. Both triangulations measured their base-line on Hounslow Heath.
"When the director of the Paris observatory, Jean Dominique Cassini, proposed in 1783 that south-east England be triangulated and that the triangulation be connected to the French network to resolve the dispute over the difference in longitude between the Greenwich and Paris observatories, Joseph Banks, president of the Royal Society and a friend of Roy, suggested that Roy should supervise the task. Roy had already begun a small triangulation in his spare time in London for his ‘own private amusement’ but also to ‘serve as a hint to the public’ of the utility of a national triangulation (O'Donoghue, 44), and he undertook the project with relish. His first task was to prepare a budget to persuade the king to subvent the Royal Society's costs. He secured royal support, but, despite being a talented and experienced administrator, he significantly underestimated the final cost of the scheme, which came to over £2000. This overrunning of budget was in fact a perennial problem in mapping projects which aspired to high scientific standards. In pursuit of those high standards Roy's next task in 1784 was to commission Jesse Ramsden to make several new instruments, including a 100 foot steel chain, six glass rods each 1 metre long, and a 3 foot theodolite, since existing instruments were inadequate for the task. Roy recognized Ramsden, his colleague from the Royal Society, as the foremost scientific instrument maker of his day. Fieldwork began with the measurement of what became known as the Hounslow Heath base. This was a line starting at King's Arbour on Hounslow Heath and extending for 5 miles in the direction of Bushy Park. The work of measuring began on 16 April 1784 and excited very considerable scientific interest; it even became something of a public spectacle after the king had made a visit to the work in progress. Ramsden's glass rods and steel chains were crucial for this work, which was completed in 1784. Roy received the Copley medal of the Royal Society the following year and won international scientific acclaim for its unprecedented accuracy". (from DNB).

Nos 46-64 Letters and Documents relating to the Thames Levelling Operations. 1829-1831
The committee was established to "consider the operations of Mr Lloyd in ascertaining the levels of the banks of the Thames and the Marsh Lands in the vicinity".
Mostly letters from JA Lloyd commenting on the Operations and on his expenses.
See CMB/1/27

Nos 65-111 Letters and Documents relating to the Southern Observatories and Charles Rumker disputed observations at Paramatta observatory. 1828-1831
Correspondence debating the need for two observatories in the southern hemisphere (at the Cape of Good Hope and Parmatta, New South Wales) and also on the dispute between Thomas Brisbane and Charles Rumker concerning the observations made by Rumker at the Parmatta observatory, when it was a private observatory owned by Rumker.

Nos 112-124 Letters and Documents relating to the use of Lightning Conductors, 1796-1827.
Lightning conductors on the Purfleet Magazine and in the West Indies [Caribbean].
See CMB/1/21 Lightning Conductors Committee.

Nos 125-128 Letters concerning the Board of Longitude, 1824-1829.
Papers relating to the abolition of the Board of Longitude.

Nos 129-150 Letters and Documents relating to Mr Babbage's Calculating Engine. 1823-1831
"...the Royal Society had consistently advised the spending of what became many thousands of pounds on the construction of Babbage's first calculating machine or difference engine through as usual a committee, which described the project as deserving of 'public encouragement'. It was not lack of support by the Society, nor of the spending of public money which caused the failure of the machine, but the fact that Babbage lost interest in his first design, wanting it to be replaced by a new, improved and even more expensive second design" (M Boas Hall, 'All Scientists Now: The Royal Society in the Nineteenth Century', CUP, 1984, p29).
See CMB/1/8 and CMB/1/26
Extent152 items
FormatManuscript and printed documents
Access statusOpen
Access conditionsOPEN - but photocopying forbidden.
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    Browse the records of some of our collections, which cover all branches of science and date from the 12th century onwards. These include the published works of Fellows of the Royal Society, personal papers of eminent scientists, letters and manuscripts sent to the Society or presented at meetings, and administrative records documenting the Society's activities since our foundation in 1660.

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