Papers concerning refinements and improvements to chronometers. The volume includes balance stopping apparatus; patent specification for W.J. Thictherner's watches; R.H. Rideout's method for compensating clocks; cheap observatory clocks by J.F. Stanistreet; experiments with sidereal clocks and their barometric inequalities; W.G. Schoof's paper on improvements in the lever escapements for chronometers; apparatus for altering the scale of compensation of chronometers; improved gimballing machines; A.J. Higham's gravity escapement; C.A. Young's detached gravity escapement; Barraud and Lunds' method for synchronising clocks; and the offer of sale of J.S. Eiffe's chronometers. The correspondents include W.H.M. Christie, D. Gill, A. d'Abbadie, C. Prichard, F.J.O. Evans, R. Hall and W. Huggins.