| RefNo | Title | Date |
| EC/1903/15 | Townsend, Sir John Sealy Edward: certificate of election to the Royal Society | |
| IM/004635 | Townsend, Sir John Sealy Edward | nd |
| RR/15/118 | Referee's report by Silvanus Phillips Thompson, on a paper 'The diffusion of ions produced in air by the action of a radio-active substance, ultra-violet light & point discharges' by John Sealy Edward Townsend | June 1900 |
| RR/16/124 | Referee's report by John Sealy Edward Townsend, on a paper 'The photo-electric discharge between metallic surfaces' by W Mansergh Varley | 10 June 1903 |
| RR/17/80 | Referee's report by John Sealy Edward Townsend, on a paper 'The ionisation produced by hot platinum in different gases' by Owen Willans Richardson | 14 July 1906 |
| RR/20/110 | Referee's report by John Sealy Edward Townsend, on a paper 'The origin of thermal ionisation from carbon' by Owen Willans Richardson | December 1913 |
| NLB/19/296 | Copy letter from Robert William Frederick Harrison, to John Sealy Edward Townsend, Fellow of the Royal Society | 28 July 1899 |
| NLB/20/792 | Copy letter from Michael Foster, to John Sealy Edward Townsend, [Fellow of the Royal Society], Trinity College, Cambridge | 10 July 1900 |
| NLB/21/38 | Copy letter from Robert William Frederick Harrison, to John Sealy Edward Townsend, [Fellow of the Royal Society], Trinity College, Cambridge | 19 July 1900 |
| NLB/26/837 | Copy letter from Robert William Frederick Harrison to, Professor John Sealy Edward Townsend, [Fellow of the Royal Society], New College, Oxford | 10 June 1903 |
| NLB/43/495 | Copy letter from Joseph Larmor, to Professor [John Sealy Edward] Townsend, Fellow of the Royal Society | 28 January 1911 |
| NLB/43/151 | Copy letter from Joseph Larmor, to Professor John [Sealy Edward] Townsend, Fellow of the Royal Society | 12 November 1910 |
| NLB/44/89 | Copy letter from Robert William Frederick Harrison to Professor J [John] S [Sealy Edward] Townsend FRS | 3 May 1911 |
| NLB/43/153 | Copy letter from Joseph Larmor, to Professor John [Sealy Edward] Townsend, Fellow of the Royal Society | 12 November 1910 |
| NLB/43/302 | Copy letter from Joseph Larmor, to Professor [John Sealy Edward] Townsend, Fellow of the Royal Society | 8 December 1910 |
| NLB/43/366 | Copy letter from Joseph Larmor, to [John Sealy Edward] Townsend, Fellow of the Royal Society | 16 December 1910 |
| NLB/48/189 | Copy letter from Robert William Frederick Harrison, to Professor [John Sealy] Townsend, Fellow of the Royal Society | 29 May 1913 |
| NLB/50/807 | Copy letter from Arthur Schuster, to Professor [John Sealy Edward] Townsend, Fellow of the Royal Society | 5 November 1914 |
| NLB/51/98 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society to Professor John Sealy Edward Townsend FRS | 11 December 1914 |
| NLB/51/638 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society to Professor John Sealy Edward Townsend FRS | 11 May 1915 |
| NLB/51/702 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society to Professor John Sealy Edward Townsend FRS | 31 May 1915 |
| NLB/51/682 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society to Professor John Sealy Edward Townsend FRS | 21 May 1915 |
| NLB/51/786 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society to Professor [John Sealy Edward] Townsend | 2 July 1915 |
| RR/17/357 | Referee's report by John Sealy Edward Townsend, on a paper 'The mobilities of the ions produced by Röntegen rays in gases and vapours' by E M Wellisch | January 1909 |
| RR/20/109 | Referee's report by John Sealy Edward Townsend, on a paper 'On a method of measuring the viscosity of the vapours of volatile liquids, with an application to bromine' by Alexander Oliver Rankine | June 1913 |
| RR/22/132 | Referee's report by John Sealy Edward Townsend, on a paper 'The electrical conducting and luminosity of flames containing salt vapours' by Harold Albert Wilson | August 1915 |
| RR/22/88 | Referee's report by John Sealy Townsend, on a paper 'Electrical effects accompanying the decomposition of organic compounds. II.-Ionisation of the gases produced during fermentation' by M C Potter | March 1915 |
| RR/31/18 | Referee's report by John Sealy Edward Townsend, on a paper 'Chemical studies in gaseous ionisation Part II' by R Winstanley Lunt | 14 July 1924 |
| RR/13/140 | Referee's report by John Henry Poynting, on a paper 'Magnetization of liquids' by John Sealy Edward Townsend | 1896 |
| RR/40/113 | Referee's report by Owen Willans Richardson, on a paper 'Ionisation by collision in monatomic gases' by John Sealy Edward Townsend and S P MacCallum | 1929 |
| RR/13/138 | Referee's report by Andrew Grey, on a paper 'Magnetization of liquids' by John Sealy Edward Townsend | 2 July 1896 |
| RR/13/139 | Referee's report by John Henry Poynting, on a paper 'Magnetization of liquids' by John Sealy Edward Townsend | 12 July 1896 |
| RR/40/24 | Referee's report by John Sealy Edward Townsend, on a paper 'The effect of water vapour on diffusion Coefficients and mobilities of ions in air' by J J Nolan and Thomas E Nevin | January 1930 |
| RR/44/105 | Referee's report by Charles Thomson Rees Wilson, on a paper 'Elastic collisions' by John Sealey Edward Townsend | July 1931 |
| RR/38/158 | Referee's report by Charles Thomson Rees Wilson, on a paper 'Motion of electrons in gases' by John Sealy Edward Townsend | August 1928 |
| RR/15/119 | Referee's report by George Francis Fitzgerald, on a paper 'The diffusion of ions produced in air by the action of a radio-active substance, ultra-violet light & point discharges' by John Sealy Edward Townsend | 30 June 1900 |
| RR/14/256 | Referee's report by John William Strutt, 3rd Baron Rayleigh, on a paper 'The diffusion of ions into gases' by John Sealy Edward Townsend | nd [May 1899] |
| RR/14/257 | Referee's report by John Henry Poynting, on a paper 'The diffusion of ions into gases' by John Sealy Edward Townsend | 10 June 1899 |
| RR/46/44 | Referee's report by John Sealy Edward Townsend, on a paper 'The effect of water vapour on the diffusion coefficients of ions in nitrogen and oxygen' by J J Nolan and A C Galvin | [December 1932] |
| RR/21/100 | Referee's report by John Sealy Edward Townsend, on a paper 'The emission of electricity from various substances at high temperatures' by George William Clarkson Kaye and W F Higgins | nd [1914] |
| NLB/61/211 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to Professor [John Sealy Edward] Townsend, FRS | 2 June 1921 |
| NLB/61/382 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to Professor [John Sealy Edeard] Townsend, FRS | 29 June 1921 |
| NLB/67/582 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Professor [John Sealy] Townsend, FRS | 25 January 1925 |
| NLB/72/681 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Professor [John Sealy Edward] Townsend, FRS | 27 February 1930 |
| NLB/66/686 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to [Robert John Strutt] Lord Rayleigh, FRS | 19 June 1924 |
| NLB/13/405 | Copy letter from A H White, to Lord Rayleigh [John William Strutt], [Secretary, Royal Society] | 21 August 1896 |
| NLB/13/127 | Copy letter from Robert William Frederick Harrison, to Richard Tetley Glazebrook, Fellow of the Royal Society | 19 June 1896 |
| RR/15/117 | Referee's report by Oliver Joseph Lodge, on a paper 'The diffusion of ions produced in air by the action of a radio-active substance, ultra-violet light & point discharges' by John Sealy Edward Townsend | June 1900 |
| RR/16/257 | Referee's report by John Sealy Edward Townsend, on a paper 'Polarised röntgen radiation' by Charles Glover Barkla | 6 February 1905 |
| RR/21/131 | Referee's report by John Sealy Edward Townsend, on a paper 'On the ionisation of gases by collision and the ionising potential for positive ions and negative corpuscles' by W I Pawlow | [April 1914] |
| RR/16/125 | Referee's report by John Sealy Edward Townsend, on a paper 'The photo-electric discharge between metallic surfaces in different gases' by W Mansergh Varley | June 1903 |
| RR/59/61 | Referee's report by John Sealy Edward Townsend, on two papers 'Ionization, excitation, and chemical reaction in uniform electric fields I - The Townsend coefficient of ionization' and 'Ionization, excitation, and chemical reaction in uniform electric fields II-The energy balance and energy efficiencies for the principal electron processes in hydrogen' by K G Emeléus, R Winstanley Lunt and C A Meek | [December 1935] |
| RR/21/91 | Referee's report by John Sealy Edward Townsend, on a paper 'On the origin of the electron emission from glowing solids' by Frank Horton | [June 1914] |
| RR/22/93 | Referee's report by John Sealy Edward Townsend, on a paper 'The influence of gases on the emission of electrons and ions from hot metals' by Owen Willans Richardson | 7 June 1915 |
| RR/31/17 | Referee's report by John Sealy Edward Townsend, on a paper 'Chemical studies in gaseous ionisation Part I' by R Winstanley Lunt | 14 July 1924 |
| RR/31/74 | Referee's report by John Sealy Edward Townsend, on a paper 'Experiments on the effects of resistance in the oscillating circuit of a triode' by J H Vincent and A L Beak | 24 January 1925 |