Correspondence and papers on telegraphic communications, including the failure of signals and breakdown of equipment; the agreement for use of the telegraph between the Admiralty and South Eastern Railway; renewal of telegraph wires in Greenwich Park; three samples of proposed cables, one being a specimen of Caoutchouc cable, with patent; notes on the arrangement of overhead wires; adjustments to the Greenwich sympathetic clock; R.L. Jones' system of clock regulation by electricity; a theory on clock regulation by electricity, with diagrams; and a paper on the South Australian telegraph. The correspondents include C.F. Varley, J. Washington, C.V. Walker, J.C. Clark, W.G. Romaine, C.T. Bright, W.T. Henley, J. Glaisher, M. Faraday and C. Wheatstone.