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The Royal Society: Science in the Making

Correspondence Explorer

Choose two people to view all letters between them.

Showing 7 letters from 1863–1864

4 letters from James Thomas Walker; 3 letters from John Frederick William Herschel

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Copy of a letter. Received tables of heights recorded in 'Sind, the Punjab, N.W. Provinces, and Central Asia.' Sees scientific interest in James Thomas Walker's described effect of refraction on levelling. Work is important to irrigation.

24 December 1863 Sender: John Frederick William Herschel Reference number: HS/18/12
1864

Autograph letter signed by sender. Received John Frederick William Herschel's two letters acknowledging receipt of 'Volume of Tables of Heights' of the Great Trigonometrical Survey of India. Hopes to visit John Frederick William Herschel and discuss phenomenon of terrestrial refraction. Received valuable assistance on tables from John Frederick William Herschel's son John.

2 January 1864 Sender: James Thomas Walker Reference number: HS/18/13

Autograph letter signed by sender. Returned from Gloucestershire. Will visit Collingwood on Monday.

6 June 1864 Sender: James Thomas Walker Reference number: HS/18/14

Autograph letter signed by sender. Sent John Frederick William Herschel 'Index Chart' of Great Trigonometrical Survey of India. Compares five triangulation methods: longitudinal series, George Everest's, G. B. Airy's, that of John Frederick William Herschel's son John, and minimum squares. John Frederick William Herschel's son and bride avoided cyclone that destroyed Calcutta Observatory.

9 December 1864 Sender: James Thomas Walker Reference number: HS/18/15

Copy of a letter. Received Indian survey chart. John Frederick William Herschel's son John wrote of higher-order ellipsoidal triangles with sides based on geodesical triangles. John Frederick William Herschel objects that these violate principle of diagonal bracing. Proposes different triangles and names sites in India as apexes. Received G. B. Airy's paper on reduction.

10 December 1864 Sender: John Frederick William Herschel Reference number: HS/18/16

Autograph letter signed by sender. Indian Triangulation chart showed progress to May 1862. Explains why arcs of meridians and parallels were chosen over diagonal braces. G. B. Airy's method of determining errors helped. Will take note and package from Maria [Herschel] to John Frederick William Herschel's son John.

15 December 1864 Sender: James Thomas Walker Reference number: HS/18/17

Copy of letter, copied as part of the correspondence project led by Colonel John Herschel FRS following the death of his father. Received Indian survey chart. John Frederick William Herschel's son John wrote of higher-order ellipsoidal triangles with sides based on geodesical triangles. John Frederick William Herschel objects that these violate principle of diagonal bracing. Proposes different triangles and names sites in India as apexes. Received G. B. Airy's paper on reduction.

10 December 1864 Sender: John Frederick William Herschel Reference number: HS/24/77