| RefNo | Title | Date |
| EC/1840/12 | Gassiot, John Peter: certificate of election to the Royal Society | |
| IM/001617 | Gassiot, John Peter | nd |
| MM/14/21 | Report on the Acton enclosures by William Tite and J P Gassiot | 23 February 1859 |
| RR/1/7 | Referee's report by John Peter Gassiot, on an unnamed paper by Peter Barlow | 16 November 1845 |
| MM/21/39 | Letter from John Peter Gassiot to George A Halsted | 29 October 1853 |
| MM/21/41 | Letter from George A Halsted to John Peter Gassiot | 16 November 1853 |
| MM/21/40 | Letter from George A Halsted to John Peter Gassiot | 3 November 1853 |
| MM/21/81 | Letter from Balfour Stewart to John Peter Gassiot | 3 March 1870 |
| DM/7/15 | Letter from J P Gassiot to William Spottiswoode, Treasurer, Royal Society | 24 December 1872 |
| MS/843/30 | Letter from John Peter Gassiot, Clapham Common, Surrey, to William Sharpey, Secretary, the Royal Society | 4 July 1871 |
| IM/Maull/001616 | Gassiot, John Peter | nd |
| IM/001618 | Gassiot, John Peter | 1853 |
| RR/4/105 | Referee's report by William Robert Grove, on a paper 'On the stratifications in electrical discharges, as observed in torricellian and other vacua - second communication' by John Peter Gassiot | 7 February 1859 |
| RR/3/110 | Referee's report by John Tyndall, on a paper 'On the stratifications and dark band in electrical discharges as observed in Torricellian vacua' by John Peter Gassiot | 25 May 1858 |
| RR/6/219 | Letter from John Peter Gassiot, to George Gabriel Stokes, regarding a paper 'Some experiments with the great induction coil at the Royal Polytechnic' by John Henry Pepper | 21 July 1869 |
| MS/257/4/433 | Copy of a letter from Balfour Stewart, Kew Observatory to [John Peter] Gassiot | 28 May 1866 |
| RR/4/109 | Letter from Charles Wheatstone, on an unnamed paper by John Peter Gassiot | 17 May 1860 |
| MC/6/52 | Letter from J P [John Peter] Gassiot, Kew Observatory, to Dr [William] Sharpey, Secretary of the Royal Society | 21 December 1859 |
| DM/7/17 | Letter from William Tite to William Spottiswoode, Treasurer, Royal Society | 27 January 1873 |
| MM/19/85 | Letter from John Peter Gassiot to Thomas Bell | 22 October 1860 |
| MM/19/90 | Letter from John Peter Gassiot to William Sharpey, Secretary, Royal Society | 20 October 1865 |
| RR/4/108 | Referee's report by Charles Wheatstone, on an unnamed paper by John Peter Gassiot | 12 March 1860 |
| MM/19/91 | Letter from Alfred Smee to John Peter Gassiot | 20 October 1865 |
| DM/7/32 | Letter from J P Gassiot to William Spottiswoode, Treasurer, Royal Society | 7 November 1873 |
| MM/14/11 | 'Account of Expenses incurred for four Balloon Ascents described in Mr Welsh's report printed in the Philosophical Transactions of 1853', by J P Gassiot | 1853 |
| IM/001357 | Deputation to Michael Faraday | nd |
| RR/4/107 | Referee's report by William Robert Grove, on a paper 'On the stratifications in electrical discharges, as observed in torricellian and other vacua - second communication' by John Peter Gassiot | 14 April 1859 |
| MC/3 | Volume 3 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1839-1843 |
| MC/3/53 | Letter from John Peter Gassiot, Clapham Common, to Dr. [Peter Mark] Roget, [Secretary of the Royal Society] | 19 November 1839 |
| MC/3/41 | Letter from John Peter Gassiot, Clapham Commons, to Dr. [Peter Mark] Roget, Secretary of the Royal Society | 26 August 1839 |
| RR/4/106 | Referee's report by John Tyndall, on an unnamed paper by John Peter Gassiot | 27 April 1859 |
| PT/23/4 | Paper, 'An account of experiments made with the view of ascertaining the possibility of obtaining a spark before the circuit of the voltaic battery is completed' by John P [Peter] Gassiot | 26 August 1839 |
| PT/75/7/2 | Diagrams, apparatuses with thermometer tubing by [John Peter Gassiot?] | [1858] |
| PT/28/2/2 | Plate, batteries and electroscopes by John Peter Gassiot | [1843] |
| PT/75/7/1 | Diagrams, stratification of mercury tubes by [John Peter Gassiot?] | [1858] |
| PT/75/8/3 | Diagrams, vacuum tube, carbonic acid generator, and glass vessels by [John Peter Gassiot?] | [1858] |
| PT/75/8/2 | Diagram, vacuum tube and carbonic acid generator by [John Peter Gassiot?] | [1858] |
| MC/5/119 | Letter from John P [Peter] Gassiot, Kew Observatory, to S H [Samuel Hunter] Christie, Secretary of the Royal Society | 24 October 1853 |
| MC/5/124 | Letter from John Tyndall, Royal Institution, to J P [John Peter] Gassiot | 18 November 1853 |
| MC/5/171 | Letter from John P [Peter] Gassiot, Chairman of the Kew Committee of the British Association, to the Earl of Rosse, President of the Royal Society | 25 June 1854 |
| MC/5/321 | Letter from John P [Peter] Gassiot, Clapham Common, to Dr [William] Sharpey, Secretary of the Royal Society | 8 December 1857 |
| MC/5/305 | Letter from John P [Peter] Gassiot, Kew Observatory, to Major General [Edward] Sabine, Treasurer of the Royal Society | 28 October 1857 |
| MC/5/164 | Letter from J F W [John Frederick William] Herschel, 32 Harley Street, to J [John] Gassiot | 24 April 1854 |
| MC/5 | Volume 5 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1851-1858 |
| MC/6 | Volume 6 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1859-1863 |
| MC/6/302 | Letter from J P [John Peter] Gassiot, Clapham Common, to G G [George Gabriel] Stokes, Secretary of the Royal Society | 19 February 1863 |
| MC/6/363 | Letter from C B [Charles Beaumont] Phipps, Windsor Castle, to Dr [William] Sharpey, [Secretary of the Royal Society] | 6 November 1863 |
| MC/8/326 | Letter from B [Balfour] Stewart, Kew Observatory, Richmond, Surrey, to J P [John Peter] Gassiot | 23 February 1869 |
| PT/28/2 | Paper, 'A description of an extensive series of the water battery; with an account of some experiments made in order to test the relation of electrical and chemical action which takes place before and after completion of the voltaic circuit' by John P [Peter] Gassiot | [1843] |
| MC/9/56 | Letter from J P [John Peter Gassiot], Clapham Common, Surrey, to Dr [William] Sharpey, [Secretary of the Royal Society] | 13 April 1870 |
| MC/9/53 | Letter from B [Balfour] Stewart, Kew Observatory, Richmond, Surrey, to J P [John Peter] Gassiot, Chairman of the Kew Committee | 9 April 1870 |
| MC/9/177 | Letter from J P [John Peter] Gassiot, Clapham Common, Surrey, to Dr [William] Sharpey, [Secretary of the Royal Society] | 13 March 1871 |
| MC/9/178 | Letter from J P [John Peter] Gassiot, Clapham Common, to Dr [William] Sharpey, Secretary of the Royal Society | 15 March 1871 |
| MC/9/205 | Letter from J P [John Peter] Gassiot, Pier Hotel, Southsea, to Walter White, [Assistant Secretary of the Royal Society] | 23 May 1871 |
| MC/9/207 | Copy letter from W S [William Spottiswoode], [Treasurer of the Royal Society], Her Majesty's Printing Office, to [John Peter] Gassiot | 26 May 1871 |
| MC/9/236 | Letter from J P [John Peter] Gassiot, Southsea, to W [William] Spottiswoode, [Treasurer of the Royal Society] | 10 July 1871 |
| AP/45/5 | Unpublished paper, 'On spectrum analysis: with a description of a large spectroscope having nine prisms and achromatic telescopes of two feet focal length' by J P [John Peter] Gassiot | 1863 |
| MC/9 | Volume 9 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1870-June 1873 |
| MC/10/37 | Letter from J P [John Peter] Gassiot, Clapham Common, Surrey, to Walter White, Assistant Secretary of the Royal Society | 11 November 1873 |
| AP/23/8 | Paper, 'An account of experiments made with the view of ascertaining the possibility of obtaining a spark before the current of the voltaic battery is completed' by J P [John Peter] Gassiot | 25 August 1839 - 19 November 1839 |
| AP/23/8/1 | Manuscript, 'An account of experiments made with the view of ascertaining the possibility of obtaining a spark before the current of the voltaic battery is completed' by J P [John Peter] Gassiot | 25 August 1839 |
| MC/10/239 | Letter from J P [John Peter] Gassiot, St John's House, Ryde, to W [William] Spottiswoode, Treasurer of the Royal Society | 19 April 1875 |
| MC/10 | Volume 10 of miscellaneous correspondence regarding business matters, sent to the Royal Society | July 1873-1876 |
| PT/28/2/1 | Manuscript, 'A description of an extensive series of the water battery; with an account of some experiments made in order to test the relation of electrical and chemical action which takes place before and after completion of the voltaic circuit' by John P [Peter] Gassiot | [1843] |
| MS/257/1/349 | Letter from Charles Chambers, Colaba Observatory [Mumbai] Bombay to [John Peter] Gassiot | 26 September 1867 |
| AP/23/8/2 | Unpublished appendix, regarding 'An account of experiments made with the view of ascertaining the possibility of obtaining a spark before the current of the voltaic battery is completed' by J P [John Peter] Gassiot | 19 November 1839 |
| AP/36/14 | Paper, 'On the vine disease in the port-wine districts of the Alto-Douro [Portugal] in April 1854' by Joseph James Forrester | 5 May 1854 |
| MS/257/4/69 | Copy of a letter from [John] Welsh, Kew Observatory to [John Peter] Gassiot | 22 October 1856 |
| AP/38/32 | Paper, 'Description of an instrument for registering changes of temperature' by Balfour Stewart | 10 June 1856 |
| AP/36/14/1 | Manuscript, 'On the vine disease in the port-wine districts of the Alto-Douro [Portugal] in April 1854' by Joseph James Forrester | 5 May 1854 |
| MS/257/2/210 | Letter from John Peter Gassiot, 77 Mark Lane to Dr Royle | 26 September 1850 |
| MS/257/2/211 | Letter from John Peter Gassiot, 77 Mark Lane to Colonel William Henry Sykes | 26 September 1850 |
| AP/45/5/1 | Unpublished manuscript, 'On spectrum analysis: with a description of a large spectroscope having nine prisms and achromatic telescopes of two feet focal length' by J P [John Peter] Gassiot | 1863 |
| AP/45/5/2 | Diagrams, prisms by John Peter Gassiot | 1863 |
| AP/45/5/4 | Diagram, spectroscope mechanism by John Peter Gassiot | 1863 |
| MC/8 | Volume 8 of miscellaneous correspondence regarding business matters, sent to the Royal Society | 1867-1869 |
| MS/257/2/208 | Letter from John Peter Gassiot, 77 Mark Lane to Dr Royle | 19 September 1850 |
| MS/257/2/209 | Letter from John Peter Gassiot, 77 Mark Lane to Colonel William Henry Sykes | 19 September 1850 |
| MS/257/4/434 | Letter from Balfour Stewart, Kew Observatory to [John Peter] Gassiot | 7 June 1866 |
| MS/257/4/432 | Copy of a letter from Balfour Stewart, Kew Observatory to [John Peter] Gassiot | 17 May 1866 |
| MS/257/4/518 | Correspondence between Balfour Stewart and [John Peter] Gassiot | [1869] |
| MS/257/1/43 | Letter from George Biddell Airy, Royal Observatory Greenwhich to John Peter Gassiot | 20 August 1866 |
| MS/257/3/381 | Letter from John Forbes Royle to [John Peter] Gassiot | 8 August 1850 |
| MS/257/4/233 | Copy of a letter from Balfour Stewart to [John Peter] Gassiot | 19th century |
| MS/257/4/514 | Letter from Balfour Stewart, Kew Observatory to [John Peter] Gassiot | 17 September 1869 |
| RR/2/50 | Referee's report by unnamed referee, on a paper [attributed] 'A description of an extensive series of the water battery; with an account of some experiments made in order to test the relation of the electrical and the chemical actions which take place before and after completion of the voltaic circuit' by John Peter Gassiot | 23 March 1844 |
| AP/23/27 | Unpublished letter, 'On Nobili's plate of colours' from J P [John Peter] Gassiot to Sir J F W [John Frederick William] Herschel | 13 January 1840 |
| PT/53/5 | Paper, 'Account of the construction of a standard barometer and description of the apparatus and processes employed in the verification of barometers at the Kew Observatory' by John Welsh | 22 May 1856 |
| RR/4/104 | Referee's report by John Tyndall, on a paper 'On the stratifications in electrical discharges, as observed in torricellian and other vacua - second communication' by John Peter Gassiot | 23 March 1859 |
| P/0147 | Deputation to Michael Faraday | c1857 |