| Reference number | Title | Date |
| EC/1865/16 | Walker, James Thomas: certificate of election to the Royal Society | |
| MM/10/84 | Letter from Col JT Walker, Mussoorie [sic], to the Government of India | 11 August 1870 |
| MM/14/105 | Letter from JT Walker, Dehra Doon, India, to Edward Sabine | c.1860s |
| NLB/12/443 | Copy letter from Theodore E James, to [Messrs Harrison & Sons] | 19 February 1896 |
| NLB/2/19 | Copy letter from Herbert Rix, to General James Thomas Walker, Fellow of the Royal Society, 13 Cromwell Road, S.W. | 7 December 1887 |
| NLB/2/772 | Copy letter from Herbert Rix, to General [James Thomas] Walker, Fellow of the Royal Society | 2 November 1888 |
| NLB/3/142 | Copy letter from Herbert Rix, to George Mathews Whipple, [Superintendent of Kew Observatory] | 26 March 1889 |
| NLB/3/21 | Copy letter from Herbert Rix, to General James Thomas Walker, Fellow of the Royal Society | 15 February 1889 |
| NLB/3/121 | Copy letter from Herbert Rix, to General James Thomas Walker | 20 March 1889 |
| NLB/3/112 | Copy letter from Herbert Rix, to General James Thomas Walker, Fellow of the Royal Society | 14 March 1889 |
| NLB/3/143 | Copy letter from Herbert Rix, to General James Thomas Walker, Fellow of the Royal Society | 26 March 1889 |
| NLB/3/229 | Copy letter from Herbert Rix, to General James Thomas Walker, Fellow of the Royal Society | 15 April 1889 |
| NLB/3/267 | Copy letter from Herbert Rix, to General James Thomas Walker, Fellow of the Royal Society | 25 April 1889 |
| NLB/3/937 | Copy letter from Herbert Rix, to General [James Thomas] Walker, Fellow of the Royal Society | 18 November 1889 |
| NLB/8/1113 | Copy letter from Herbert Rix, to General James Thomas Walker, Fellow of the Royal Society | 27 February 1894 |
| NLB/11/565 | Copy letter from Herbert Rix, to Mr G Pearson, 3 Bolt Court, Fleet Street, E.C. | 24 July 1895 |
| NLB/11/550 | Copy letter from an unknown correspondent, to Mr George Pearson, Engraver, 3 Bolt Court, Fleet Street, E.C. | 22 July 1895 |
| NLB/11/543 | Copy letter from Herbert Rix, to General [James Thomas] Walker, Fellow of the Royal Society | 19 July 1895 |
| NLB/11/533 | Copy letter from Herbert Rix, to General [James Thomas] Walker, Fellow of the Royal Society | 17 July 1895 |
| NLB/11/744 | Copy letter from Herbert Rix, to General [James Thomas] Walker, Fellow of the Royal Society, Costylost, Washaway, Cornwall | 30 September 1895 |
| NLB/11/719 | Copy letter from Herbert Rix, to General [James Thomas] Walker, Fellow of the Royal Society, Costylost, Washaway, Cornwall | 24 September 1895 |
| NLB/11/832 | Copy letter from Herbert Rix, to General James Thomas Walker, Fellow of the Royal Society | 14 October 1895 |
| RR/12/401 | Referee's report by Alexander Ross Clarke, on a paper 'India's contribution to geodesy' by James Thomas Walker | 27 May 1895 |
| RR/12/403 | Referee's report by Charles William Wilson, on a paper 'India's contribution to geodesy' by James Thomas Walker | 6 July 1895 |
| RR/12/402 | Referee's report by George Howard Darwin, on a paper 'India's contribution to geodesy' by James Thomas Walker | 8 June 1895 |
| MS/427/430 | Copy letter from [Thomas Henry] Huxley, President of the Royal Society; to the Astronomer Royal [William Henry Mahoney Christie] | 23 May 1885 |
| MM/10/85 | Copy of letter from Col JT Walker, Dehra Doon, to Sir Edward Sabine | 11 August 1870 |
| MC/9/405 | Letter from J T [James Thomas] Walker, 17 Queensberry Place, South Kensington, to Professor [George Gabriel] Stokes, Secretary of the Royal Society | 29 August 1872 |
| MC/7/63 | Draft letter from Major-General Edward Sabine, President of the Royal Society, Burlington House, to Colonel J T [James Thomas] Walker RE, 47 Beaufort Gardens | 30 April 1864 |
| MC/7/93 | Letter from J [James] Challis, Plumian Professor of astronomy, University of Cambridge, Cambridge, to General [Edward] Sabine, [President of the Royal Society] | 11 June 1864 |
| MC/7/147 | Letter from Lieutenant-Colonel J T [James Thomas] Walker, Surveyor Trigonometrical Survey of India, 1 Cromwell Road, South Kensington, to the Royal Society | 29 November 1864 |
| MC/7/67 | Letter from Lieutenant-Colonel J T [James Thomas] Walker RE, Superintendent General for the Trigonometrical Survey of India, 24 Blessington Road, to [Thomas Baring], the Under Secretary of State for India, Military Department | 12 May 1864 |
| MC/7/348 | Letter from Lieutenant-Colonel J T [James Thomas] Walker, Dehra Doon, Bombay, to General [Edward] Sabine, [President of the Royal Society] | 31 July 1866 |
| MC/7/258 | Letter from Lieutenant-Colonel J T [James Thomas] Walker, Dehra Doon, Bombay, to W [William] Sharpey, [Secretary of the Royal Society] | 18 September 1865 |
| MC/7 | Volume 7 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1864-1866 |
| MC/8/74 | Letter from J T [James Thomas] Walker, Dehra Doon, Bombay, to General [Edward] Sabine, President of the Royal Society | 17 August 1867 |
| MC/9 | Volume 9 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1870-June 1873 |
| MS/257/5/38 | Copy of a letter from James Thomas Walker, Dehra Doon [Dehradun], to Edward Sabine | 11 August 1870 |
| MS/257/5/39 | Letter from James Thomas Walker, 29 Alfred Place West to Edward Sabine | 28 February 1871 |
| MC/8 | Volume 8 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1867-1869 |
| RR/11/212 | Referee's report by James Thomas Walker, on the Bakerian Lecture 'On the grand currents of atmospheric circulation' by James Thomson | 16 May 1892 |
| AP/63/6 | Unpublished paper, 'Report on tidal disturbances caused by volcanic eruptions at Java 26th - 27th August 1883 and the propagations of the "supertidal" waves' by [Andrew Wilson] Baird | 4 December 1883 |
| PP/15/14 | Paper, 'On the unit of length of a standard scale by Sir George Shuckburgh, appertaining to the Royal Society' by [James Thomas] Walker | 1 February 1890 |
| MS/257/5/36 | Letter from James Thomas Walker, Dehra Doon [Dehradun], to Edward Sabine | 2 January 1868 |
| MS/257/5/37 | Copy of a letter from James Thomas Walker, Dehra Doon [Dehradun], to Balfour Stewart | 3 January 1868 |
| PP/23/13 | Paper, 'Terrestrial refraction in the Western Himalayan Mountains' by James Thomas Walker | 12 January 1894 |
| RR/12/40 | Referee's report by James Thomas Walker, on a paper 'Harmonic analysis of hourly observations of air temperature and pressure at British observatories.—part I. Temperature' by Richard Strachey | 3 April 1893 |
| MC/14/94 | Letter from Warren de la Rue, Chairmain, Kew Observatory, Richmond, to the Secretary of the Royal Society | 27 November 1885 |
| RR/11/16 | Referee's report by James Thomas Walker, on a paper 'On hindoo [sic] astronomy' by William Brennand | 6 January 1892 |
| MC/16/145 | Letter from [James Thomas] Walker, Dresden, to Professor [Michael] Foster | 16 July 1894 |
| MC/14 | Volume 14 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1885-1888 |
| MC/16 | Volume 16 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1893-1896 |
| HS/18/14 | Letter, from James Thomas Walker to Sir John Herschel, dated at 24 Blessington Road, Lee, [Blackheath] | 6 June 1864 |
| HS/18/13 | Letter, from James Thomas Walker to Sir John Herschel, dated at 24 Blessington Road, Lee, Blackheath | 2 January 1864 |
| HS/18/12 | Copy letter, from Sir John Herschel to James Thomas Walker, dated at Collingwood | 24 December 1863 |
| HS/18/17 | Letter, from James Thomas Walker to Sir John Herschel, dated at 1 Cromwell Road, South Kensington | 15 December 1864 |
| HS/18/15 | Letter, from James Thomas Walker to Sir John Herschel, dated at 1 Cromwell Road, South Kensington | 9 December 1864 |
| HS/18/16 | Copy letter, from Sir John Herschel to James Thomas Walker, dated at Collingwood | 10 December 1864 |