Correspondence with tradesmen, initials A-M, including letters from booksellers; coal merchants; clock repairers; horologists; builders; chandlers; merchants; machine repairers; instrument makers; opticians; the Kent Water Company; parcel carriers; engineers; chemists; photographic suppliers; journeymen; bookbinders; assayers; plumbers; stove makers; the Electric and Telegraph Company; gas fitters; and a photographer. The letters cover various instructions; requests; accounts; bills; invoices; receipts; circulars; tenders; routine repairs; and adjustments and improvements to instruments. There are also notes by J. Glaisher and a graph of human respiration and pulse rates.