The collection is comprised of papers relating to James Clerk Maxwell, George Chrystal, Prof. William Garnett (Maxwell's Demonstrator at the Cavendish Laboratory), and John William Strutt, Lord Rayleigh. A typed note states '5.10.67: Presented by Professor Mott, these were found among the possessions of his late Father, who worked in the Cavendish Laboratory for two years in the early days'. The miscellaneous items, nos. 22-26, are in Maxwell's hand.
1-21. Letters from Maxwell to Chrystal and Garnett, 1874-1879. Maxwell was writing from Glenair and the Cavendish Laboratory, Cambridge, with the exception of one letter from 11 Scroop Terrace, Cambridge.
22. Unaddressed testimonial on behalf of Chrystal, 1879 (enclosed with no. 21).
23. Page of bridge calculations, with a sketch.
24. Page of a dynamometer sketch, with data.
25. Reference to Peter's Recherches sur la parallaxe des toiles fixes.
26. Instructions for an experiment entitled 'Unit of Resistance by Wippe and Differential Galvanometer'.
27. Continuation of no. 26, with calculations.
28-33. Letters from Lord Raleigh to Chrystal, 1880-1885.