The paper was deduced from a series of experiments, made on the London Dock Works with blue lias and Dorking limes; and at Leith Docks with the limes in the neighbourhood of Edinburgh, and with cements both natural and artificial. A short account was first given of the nature of the experiments at the London Docks, with the points investigated. A longer and more professional account of these is to be found in the Transactions of the Institution of Civil Engineers for 1857–58.