Miscellaneous correspondence concerning new inventions and engineering works, including proposals for a bridge at Limehouse, London, in conjunction with the Metropolitan District Railway, depicted on a map, with comments by Airy; calculations relating to curves in railway tracks; Airy's theory of the link motion for the sliding value of steam engines'; various inventions for propellers, steering apparatus and paddles, with Airy's views; T. Walker's plan for recycling sewage, including a plan of a pump and his sounding instrument; J. Schumacher's floating breakwater, with drawings; investigations into the strength of an iron arch and theories of couples and strains; J. Steele's pendulum experiments; improvements to Portsmouth Harbour; an article from the 'Iron Trade Circular (Rylands')' on iron mines around North Tyne; and the notices and membership of the Institution of Civil Engineers, with its presidential address by J.R. McClean. The correspondents include J. Fowler, W. De La Rue, J. Coode, A. de Morgan, W.H. Barlow, G.G. Stokes, W. Fairbairn and E.J. Routh.