Correspondence with tradesmen, including letters from booksellers; coal merchants; clock repairers; horologists; chandlers; merchants; instrument makers; parcel carriers; engineers; chemists; decorators; journeymen; bookbinders; import agents; gas fitters; and printers. The letters cover various instructions; requests; accounts; invoices; bills; receipts; tenders; circulars; routine repairs; and adjustments and improvements to instruments. There are letters from F.A.T. Winnecke, E. Dunkin, O. Struve, C.F. Varley, C.V. Walker, W. De La Rue and J. Glaisher; a brochure for Chubb's locks; correspondence on the products of the Gutta Percha Company; and a price list of chemicals provided by Jackson and Towson.