| Reference number | Title | Date |
| MM/17/27 | Letter from Charles Meldrum to Walter White, Assistant Secretary, Royal Society | 10 February 1871 |
| NLB/15/756 | Copy letter from Theodore E James, to Messrs Harrison & Sons | 2 December 1897 |
| NLB/6/719 | Copy letter from Theodore E James, to Harrisons | 1 July 1892 |
| NLB/14/226 | Copy letter from Theodore E James, to Messrs Harrison & Sons | 25 January 1897 |
| NLB/16/652 | Copy letter from Robert William Frederick Harrison, to Theodore E James, to Messrs Harrison & Sons | 16 May 1898 |
| NLB/14/552 | Copy letter from Theodore E James, to Charles Meldrum, Fellow of the Royal Society | 27 March 1897 |
| NLB/20/301 | Copy letter from Robert William Frederick Harrison, to Mr W Parker, Parcels Department, Euston Station, N.W. | 15 March 1900 |
| MS/257/3/116 | Letter from Charles Meldrum, 3 Greenside, Richmond to Edward Sabine | 1 February 1867 |
| AP/58/4/5 | Unpublished letter, regarding 'On a secular variation in the rainfall in connection with the secular variation in the amount of sun-spots' from John Allan Broun to George Gabriel Stokes | 8 January 1877 |
| RR/8/51 | Referee's report by Warren de la Rue, on a paper 'On a secular variation in the rainfall in connexion with the secular variation in amount of sun-spots' by Charles Meldrum | 2 July 1877 |
| MS/257/3/119 | Letter from Charles Meldrum, Kew Observatory to Edward Sabine | 15 February 1867 |
| AP/58/4/2 | Unpublished appendix, 'Reply to objections to Mr Meldrum's paper on rainfall and sunspots' by Charles Meldrum | 19 September 1876 |
| MC/9/511 | Letter from C [Charles] Meldrum, Observatory Mauritius, to Sir Edward Sabine | 7 March 1873 |
| EC/1876/15 | Meldrum, Charles: certificate of election to the Royal Society | |
| MS/516/5/3 | Extract of a letter from [Charles] Meldrum to [Robert Henry] Scott | 26 January 1884 |
| MC/8/155 | Letter from C [Charles] Meldrum, 8 Bedford Place, Russell Square, London, to Lieutenant General [Edward] Sabine, President of the Royal Society | 18 March 1868 |
| MS/257/3/118 | Letter from Charles Meldrum, 3 Greenside, Richmond to Edward Sabine | 9 February 1867 |
| MC/9 | Volume 9 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1870-June 1873 |
| AP/58/4/3 | Unpublished letter, regarding 'On a secular variation in the rainfall in connection with the secular variation in the amount of sun-spots' from Balfour Stewart to unknown recipient | 12 July 1876 |
| MC/10/440 | Letter from C [Charles] Meldrum, Observatory Mauritius, to Professor [George Gabriel] Stokes, Secretary of the Royal Society | 17 August 1876 |
| MC/10/441 | Letter from C [Charles] Meldrum, Observatory Mauritius, to Walter White, Assistant Secretary of the Royal Society | 17 August 1876 |
| MC/10 | Volume 10 of miscellaneous correspondence regarding business matters, sent to the Royal Society | July 1873-1876 |
| AP/58/4 | Unpublished paper, 'On a secular variation in the rainfall in connection with the secular variation in the amount of sun-spots' by C [Charles] Meldrum | 1876-1877 |
| AP/58/4/4 | Unpublished letter, regarding 'On a secular variation in the rainfall in connection with the secular variation in the amount of sun-spots' from G G [George Gabriel] Stokes to the referees of Charles Meldrum's paper | [1876] |
| MS/257/3/121 | Letter from Charles Meldrum, Kew Observatory to Edward Sabine | 27 February 1867 |
| MS/257/3/123 | Letter from Charles Meldrum, Kew Observatory to Edward Sabine | 15 March 1867 |
| MS/257/3/113 | Letter from Charles Meldrum, Mauritius to Edward Sabine | 18 February 1865 |
| MS/257/3/117 | Letter from Charles Meldrum, 3 Greenside, Richmond to Edward Sabine | 4 February 1867 |
| MS/257/3/114 | Letter from Charles Meldrum, Mauritius to Edward Sabine | 7 March 1865 |
| MS/257/3/120 | Letter from Charles Meldrum, Kew Observatory to Edward Sabine | 18 February 1867 |
| MS/257/3/124 | Letter from Charles Meldrum, 15 Broughton [Place], Edinburgh to Edward Sabine | 21 November 1867 |
| AP/58/4/1 | Unpublished manuscript, 'On a secular variation in the rainfall in connection with the secular variation in the amount of sun-spots' by C [Charles] Meldrum | 6 January 1876 |
| MC/8 | Volume 8 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1867-1869 |
| AP/65/1/1 | Unpublished manuscript, 'On Meldrum's rules for handling ships in the Southern Indian Ocean' by Ralph Abercromby | 1888 |
| AP/65/1 | Unpublished paper, 'On Meldrum's rules for handling ships in the Southern Indian Ocean' by Ralph Abercromby | 1888 |
| MS/257/3/125 | Letter from Charles Meldrum, 107 King Street, Aberdeen to Mrs Sabine | 4 January 1868 |
| PP/5/22 | Paper, 'Report to the Solar Physics Committee on a comparison between apparent inequalities of short period in sun-spot areas and in diurnal temperature ranges at Toronto and Kew' by Balfour Stewart and William Lant Carpenter | 1884 |
| PP/5/22/1 | Manuscript, 'Report to the Solar Physics Committee on a comparison between apparent inequalities of short period in sun-spot areas and in diurnal temperature ranges at Toronto and Kew' by Balfour Stewart and William Lant Carpenter | 1884 |
| MS/257/3/110 | Letter from Charles Meldrum, Mauritius to Edward Sabine | 7 December 1854 |
| MS/257/3/126 | Letter from Charles Meldrum, Mauritius to Edward Sabine | 1 July 1870 |
| MS/257/3/122 | Letter from Charles Meldrum, Kew Observatory to Edward Sabine | 12 March 1867 |
| MS/257/3/115 | Letter from Charles Meldrum, S S Norseman to Edward Sabine | 22 December 1866 |
| MS/257/3/111 | Letter from Charles Meldrum, Mauritius to Edward Sabine | 6 September 1860 |
| MS/257/3/112 | Letter from Charles Meldrum, Mauritius to Edward Sabine | 6 February 1863 |
| MS/516/9/1 | Letter from [Charles]Todd, Adelaide, and [Charles] Meldrum, Mauritius, collected by the [Royal Society Krakatoa Committee] | February 1884 |