Correspondence concerning new techniques and discoveries, including O.M. Mitchel's method of recording transits and north polar distances; a paper on J. Locke's electro-chronograph for the House of Representatives; conducted experiments and newspaper articles; the velocity of the galvanic current through telegraph wires, from 'The Daily Evening Traveller'; a clock for uniform motion by W.H. Miller, with drawings; a paper by Sir W. Siemens, in French, on telegraphs; M.J. Johnson's heliometer; a double image micrometer; a double image eyepiece; new eyepieces; and the new transit circle at Greenwich. There are computations by R.C. Carrington for the erection of an instrument, various calculations for errors, and numbers for sliding rules for collimation level and azimuth error. The correspondents include Sir F. Beaufort, C.P. Smyth, W. Lassell and A. de Morgan. There is also an engraving of 'Mr H-nk-s's Orrerys'.