Correspondence with tradesmen, initials N-W, including letters from opticians; booksellers; stationers; engineers; and instrument makers. The correspondents include C.A.F. Peters and E. Sabine. There is a price list for writing on architecture and engineering; a diagram of the breech end of a telescope; and ten plans from Ransome and Sims of galvanic rings for the polar axis, a holdfast for the Dome, clamps and slow-motion apparatus for the Hour Circle, an observer's chair, etc.