| RefNo | Title | Date |
| EC/1898/11 | Parsons, Sir Charles Algernon: certificate of election to the Royal Society | |
| MS/525/5/2/50 | Letter from Charles Algernon Parsons, Ray, Kirkwhelpington, Northumberland, to [Robert Harrison] Assistant Secretary, Royal Society | 21 August 1915 |
| MS/525/5/4/5 | Receipt from Sir Charles Algernon Parsons, 5 Carlos Place, to [Dugald] Clerk | 14 January 1917 |
| MS/525/5/2/44 | Telegram from Charles Parsons, Newcastle-upon-Tyne, to Dugald Clerk, Holborn, London | 14 July 1915 |
| NLB/64/92 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to Sir Charles [Algernon] Parsons, FRS | 30 June 1923 |
| MS/525/6/6/3/2 | Letter from Charles Algernon Parsons, C A Parsons and Company Limited, Heaton Works, Newcastle-on-Tyne, to [Dugald] Clerk | 6 May 1915 |
| MS/525/6/6/3/15 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Newcastle-on-Tyne, to [Dugald] Clerk | 8 July 1915 |
| MS/525/6/6/3/12 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Northumberland, to [Dugald] Clerk | 23 June 1915 |
| MS/525/6/6/3/11 | Letter from Charles Algernon Parsons, C A Parsons and Company Limited, Heaton Works, Newcastle-on-Tyne, to [Dugald] Clerk | 17 June 1915 |
| MS/525/5/5/15 | Letter from Charles Algernon Parsons, 6 Windsor Terrace, Newcastle-on-Tyne, to [Robert Harrison] | 14 February 1919 |
| MS/525/6/8/11 | Letter from Charles Algernon Parsons, 8 Victoria Street, London, to [Dugald] Clerk | 5 August 1915 |
| MS/525/6/6/3/26 | Telegram from Charles Algernon Parsons, Newcastle, to Dugald Clerk, Holborn | 13 August 1915 |
| MS/525/6/6/3/20 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Newcastle-on-Tyne, to [Dugald] Clerk | 25 July 1915 |
| MS/525/6/6/3/4 | Mine equilibrium apparatus: description [by C A Parsons and Company Limited] | 7 May 1915 |
| MS/525/6/6/3/19 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Newcastle-on-Tyne, to [Dugald] Clerk | 16 July 1915 |
| MS/525/6/6/3/16 | Telegram from 'Turbo' [Charles Parsons], Newcastle-on-Tyne, to Dugald Clerk, Holborn, London | 14 July 1915 |
| MS/525/6/6/3/5 | Mine equilibrium apparatus: engineering drawing [by C A Parsons and Company Limited] | 7 May 1915 |
| MS/525/6/6/3/7 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Northumberland, to [Dugald] Clerk | 24 May [1915] |
| MS/525/6/6/3/6 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Northumberland, to [Dugald] Clerk | 16 May [1915] |
| MS/525/6/6/3/1 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Northumberland, to [Dugald] Clerk | 4 May 1915 |
| MS/525/6/6/2/29 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Northumberland, to [Dugald] Clerk | 27 April [1915] |
| MS/525/6/6/3/25 | Letter from Charles Algernon Parsons, C A Parsons and Company Limited, Heaton Works, Newcastle-on-Tyne, to [Dugald] Clerk | 13 August 1915 |
| MS/525/6/6/3/28 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Newcastle-on-Tyne, to [Dugald] Clerk | 15 August 1915 |
| MS/525/6/6/3/22 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Northumberland, to [Dugald] Clerk | 6 August 1915 |
| MS/525/6/6/3/40 | Letter from Charles Algernon Parsons, 6 Windsor Terrace, Newcastle-on-Tyne, to [Dugald] Clerk | 18 December 1915 |
| MS/525/6/8/12 | Telegram from Charles Algernon Parsons, Newcastle on Tyne, to Dugald Clerk, c/o Marklerk, Holborn, London | 9 August 1915 |
| MS/525/6/6/3/32 | Letter from Charles Algernon Parsons, C A Parsons and Company Limited, Heaton Works, Newcastle-on-Tyne, to [Dugald] Clerk | 23 August 1915 |
| MS/525/6/6/3/39 | Letter from Charles Algernon Parsons, Ray, Kirkwelpington, Newcastle-on-Tyne, to [Dugald] Clerk | 3 October 1915 |
| IM/006476 | Sir James Alfred Ewing, Sir Charles Algernon Parsons and Sir Dugald Clerk | 1910 |
| NLB/17/690 | Copy letter from Theodore E James, the Honourable Charles Algernon Parsons, Fellow of the Royal Society | 8 December 1898 |
| NLB/16/596 | Copy letter of a notice from Robert William Frederick Harrison, to [The Times] | 5 May 1898 |
| NLB/20/594 | Copy letter from Robert William Frederick Harrison, to Charles Algernon Parsons, Fellow of the Royal Society | 28 May 1900 |
| NLB/23/2/254 | Copy letter from Sir Michael Foster, to The Deputy Master, Royal Mint, E. | 6 November 1902 |
| NLB/23/2/256 | Copy letter from Sir Michael Foster, to The Honorable Charles A Parsons, Fellow of the Royal Society | 6 November 1902 |
| NLB/25/714 | Copy letter from Robert William Frederick Harrison, to Charles Algernon Parsons, Fellow of the Royal Society | 12 December 1902 |
| NLB/28/305 | Copy letter from Robert William Frederick Harrison, to the Honorable Charles Algernon Parsons, Fellow of the Royal Society | 16 February 1904 |
| NLB/28/564 | Copy letter from Robert William Frederick Harrison, to the Honorable Charles Algernon Parsons, Fellow of the Royal Society | 30 March 1904 |
| NLB/28/617 | Copy letter from Robert William Frederick Harrison, to the Honorable Charles Algernon Parsons, Fellow of the Royal Society | 18 April 1904 |
| NLB/28/781 | Copy letter from Robert William Frederick Harrison, to Sir John G T Sinclair, Travellers' Club, Pall Mall, S.W. | 18 May 1904 |
| NLB/35/90 | Copy letter from Robert William Frederick Harrison, to Charles Algernon Parsons, Heaton Works, Newcastle on Tyne | [15 April 1907] |
| NLB/34/353 | Copy letter from Robert William Frederick Harrison, to The Honorable Charles Algernon Parsons, Fellow of the Royal Society | 9 January 1907 |
| NLB/36/768 | Copy letter from Robert William Frederick Harrison, to Messrs Robarts Lubbock & Company | 12 December 1907 |
| NLB/37/509 | Copy letter from Robert William Frederick Harrison to Harrison & Sons | 31 March 1908 |
| NLB/37/511 | Copy letter from the Royal Society to The Editor of "The Chemical News", 16 Newcastle Street, Farringdon Street, EC | 31 March 1908 |
| NLB/44/290 | Copy letter from Robert William Frederick Harrison to the Honourable C [Charles] A [Algernon] Parsons FRS | 8 June 1911 |
| NLB/37/754 | Copy letter from Robert William Frederick Harrison to The Honorable C [Charles] A [Algernon] Parsons, Fellow of the Royal Society | 8 May 1908 |
| NLB/41/323 | Copy letter from Robert William Frederick Harrison, to The Honorable Charles Algernon Parsons, Fellow of the Royal Society | 22 November 1909 |
| NLB/40/341 | Copy letter from Robert William Frederick Harrison to The Honorable C [Charles] A [Algernon] Parsons FRS | 26 May 1909 |
| NLB/41/96 | Copy letter from Robert William Frederick Harrison, to The Honorable Charles Algernon Parsons, Fellow of the Royal Society | 13 October 1909 |
| NLB/70/196 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to the Honourable Sir Charles Parsons, KCB, FRS | 31 January 1927 |
| NLB/42/623 | Copy letter from Robert William Frederick Harrison to The Honourable C [Charles] A [Algernon] Parsons FRS | 19 July 1910 |
| NLB/47/279 | Copy letter from Robert William Frederick Harrison to Sir Charles Parsons, KCB, FRS | 9 January 1913 |
| NLB/45/29 | Copy letter from Robert William Frederick Harrison to the Honourable Sir C [Charles] A [Algernon] Parsons KCB | 11 December 1911 |
| NLB/59/516 | Copy letter from Edwin Deller, Assistant Secretary of the Royal Society; to Sir Charles [Algernon] Parsons, FRS | 11 October 1920 |
| NLB/47/55 | Copy letter from Robert William Frederick Harrison to the Hon Sir Charles Parsons KCB, FRS | 20 November 1912 |
| NLB/51/382 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society to The Hon. Sir Charles Parsons KCB, FRS | 5 March 1915 |
| NLB/50/346 | Copy letter from Robert William Frederick Harrison, to The Honorable Sir Charles Parsons, Fellow of the Royal Society | 22 June 1914 |
| NLB/52/318 | Copy letter from [Robert William Frederick Harrison, Assistant Secretary of the Royal Society]; to Sir Charles Parsons, FRS | 9 November 1915 |
| NLB/54/214 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to Messrs Harrison & Sons | 6 March 1917 |
| NLB/54/830 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to [Messrs Harrison & Sons] | 15 October 1917 |
| NLB/53/235 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to The Hon. Sir Charles Parsons, K.C.B., FRS | 06 June 1916 |
| NLB/58/815 | Copy letter from David Prain, Treasurer of the Royal Society; to Sir Charles [Algernon] Parsons, FRS | 21 June 1920 |
| NLB/55/154 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to The Hon. Sir Charles [Algernon] Parsons, K.C.B., FRS | 21 December 1917 |
| NLB/59/872 | Copy letter from Edwin Deller, Assistant Secretary of the Royal Society; to Sir Charles [Algernon] Parsons, FRS | 24 November 1920 |
| NLB/56/190 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to Sir Charles [Algernon] Parsons, FRS | 12 December 1918 |
| NLB/53/307 | Copy letter from [Alfred Bray] Kempe, Treasurer of the Royal Society; to The Honourable Sir Charles [Algernon] Parsons, K.C.B., FRS | 06 July 1916 |
| NLB/56/233 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to Sir Charles Parsons, FRS | 18 December 1918 |
| NLB/56/195 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to Sir Charles [Algernon] Parsons, FRS | 13 December 1918 |
| NLB/53/309 | Copy letter from [Alfred Bray] Kempe, Treasurer of the Royal Society; to The Honorable Sir Charles [Algernon] Parsons, K.C.B., FRS | 06 July 1916 |
| NLB/59/810 | Copy letter from Edwin Deller, Assistant Secretary of the Royal Society; to Sir [Charles] Algernon Parsons, FRS | 15 November 1920 |
| NLB/53/96 | Copy letter from Robert William Frederick Harrison, Assistant Secretary of the Royal Society; to The Hon. Sir Charles Parsons, K.C.B, FRS | 10 April 1916 |
| AP/79/11 | Unpublished paper, 'The ignition of gases at reduced pressure by continuous current break-sparks, and ionisation' by W M Thornton | 1916 |
| NLB/57/726 | Copy letter from AH White, Assistant Librarian of the Royal Society; to Sir Charles [Algernon] Parsons, FRS, KCB | 29 January 1920 |
| NLB/55/525 | Copy letter from [Joseph John] Thomson, President of the Royal Society; to The Hon. Sir Charles Parsons, K.C.B., FRS | 16 May 1918 |
| NLB/64/127 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to Sir Charles [Algernon] Parsons, FRS | 5 February 1923 |
| NLB/64/189 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Sir Charles [Algernon] Parsons, FRS | 21 February 1923 |
| NLB/63/605 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to The Honourable Sir Charles Parsons, K.C.B., FRS | 13 November 1922 |
| NLB/64/820 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to The Hon. Sir Charles [Algernon] Parsons, FRS | 26 June 1923 |
| NLB/64/788 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to the Hon. Sir Charles [Algernon] Parsons FRS | 19 June 1923 |
| NLB/65/394 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to the Honourable Sir Charles [Algernon] Parsons, KCB, FRS; also sent to Professor [Charles Glover] Barkla, Professor [Arthur Stanley] Eddington, Sir [William Henry] Bragg, Professor [Thomas Ralph] Merton, Professor [Jocelyn Field] Thorpe, Sir [Frederick William] Andrewes, Professor [Edwin Stephen] Goodrich, Sir [Thomas Henry] Holland and Sir [Frederick William] Keeble. | 25 October 1923 |
| NLB/71/654 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Sir Ernest Rutherford, O.M., President of the Royal Society | 26 September 1928 |
| NLB/68/715 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to the Honourable Sir Charles Parsons, KCB, FRS | 21 October 1925 |
| NLB/69/246 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to the Secretary, British Association | 12 February 1926 |
| NLB/68/946 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to the Honourable Sir Charles Parsons, KCB, FRS | 4 December 1925 |
| NLB/71/954 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to The Hon. Sir Charles [Algernon] Parsons, K.C.B., FRS | 17 December 1928 |
| NLB/71/188 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to [Stanley Smith] Cook Esq. | 4 February 1928 |
| NLB/71/808 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to to the Hon.Sir Chalres [Algernon] Parsons, O.M., K.C.B., FRS | 1 November 1928 |
| NLB/72/463 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to Sir Charles Parsons, OM, KCB, FRS | 5 November 1929 |
| NLB/73/210 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to the Editor of 'The Times' | 2 March 1931 |
| NLB/73/196 | Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to A. D. C. Parsons Esq., SW1 | 19 February 1931 |
| NLB/71/187 | Copy letter from James Hopwood Jeans, Secretary of the Royal Society; to Sir Charles [Algernon] Parsons, O.M., K.C.B., FRS | 26 January 1928 |
| MS/525/6/10/7 | Copy letter, Charles Algernon Parsons, Holeyn Hall, Wylam-on-Tyne, to [Archibald] Barr | 14 March 1915 |
| MS/525/6/6/3/31 | Copy letter from Charles Algernon Parsons, Junior Carlton Club, Pall Mall, to [Dugald] Clerk | 18 August 1915 |
| MS/525/6/6/3/3 | Letter from Charles Algernon Parsons, C A Parsons and Company Limited, Heaton Works, Newcastle-on-Tyne, to [Dugald] Clerk | 7 May 1915 |
| NLB/35/280 | Copy letter from Robert William Frederick Harrison, to Professor Arthur Schuster, Fellow of the Royal Society, Chairman of the Physics and Chemistry Committee | 10 May 1907 |
| RR/17/207 | Referee's report by William Crookes, on a paper 'The conversion of diamond into coke in high vacuum by cathode rays' by Charles Algernon Parsons and Alan Archibald Campbell Swinton | 10 January 1908 |
| RR/25/42 | Referee's report by Robert Abbott Hadfield, on the Bakerian Lecture 'Experiments on the artificial production of diamond' by Charles Algernon Parsons | nd [1918] |
| NLB/32/286 | Copy letter from Robert William Frederick Harrison, to Dugald Clerk, 18 Southampton Buildings, Chancery Lane, E.C. | 13 February 1906 |
| NLB/52 | New Letter Book volume 52, copy letters sent from Royal Society administration | 9 July 1915-8 March 1916 |
| PT/62/8/57 | Photograph, Lord Rosse's telescope at Birr Castle, Ireland by [Mary Parsons, Countess of Rosse?] | [1857] |
| PT/62/8/58 | Photograph, Lord Rosse's telescope at Birr Castle, Ireland by [Mary Parsons, Countess of Rosse?] | [1857] |
| AP/79/20 | Unpublished paper, 'The influence of reduced pressure upon the electrical ignition of gases' by W M Thornton | 1918 |
| RR/25/41 | Referee's report by John Allen Harker, on the Bakerian Lecture 'Experiments on the artificial production of diamond' by Charles Algernon Parsons | [October 1918] |
| NLB/41/789 | Copy letter from Robert William Frederick Harrison, to The Honorable Charles Algernon Parsons, Fellow of the Royal Society | 25 February 1910 |