of the diver, it is capable of lifting. Many thousand pounds’ worth of property is now lying at the bottom of the sea and rivers, which seems a pity when so simple a method can bring them again to “_terra firma_.” After this Lecture, which was illustrated in a large tank of water in the centre of the Great Hall of the Institution, we walked around to look at the immense collection of models of all new discoveries in science. There was the magnificent model of the Britannia Bridge.—The machinery, which commences by taking the cotton from the pod, cleans it from the seed by means of rollers; then it is passed through another instrument called a carding machine, being a series of wires so placed as to tear the cotton asunder, and lay it in a beautiful sheet on the surfaces of the wires; from thence it is collected by a most elegant and ingenious contrivance, formed into a fillet, and then placed on the roving frame; thence it passes into the spinning frame and becomes thread, which is again used in an exhibition of the lace manufacture, by a beautiful model machine. In close proximity to this machine, we observe a model lighthouse, fixed on a black substance for its base: this substance is very curious, and requires a little explanation. In Trinidad, in the West Indies, there is a Lake of Bitumen. A stream of this Bitumen (which you know is a sort of pitch) flowed in distant ages, through a channel two thousand yards in length to the beach, and thence six hundred yards into the sea, carrying with it all the loose materials encountered in its progress. This now constitutes a promontory, whereon the action of the waves and atmosphere, under a tropical sun, have had no deteriorating effect. This fact led to investigation, and now it is used as foundations to lighthouses, piers, jetties, bridges, &c., as well as water-pipes, instead of lead, which you know will combine chemically with the constituents of water, and convert that water into a deleterious compound. When Admiral, the Earl of Dundonald, (to whom this pitch belongs,) was Commander-in-Chief of the West India Station, he made many experiments on this wonder of nature, and has patented its application to very many useful purposes; his lordship laid down, from the lake to the shore, a series of pipes, which were manufactured by his sailors, and which pipes enabled the ships on the station to obtain excellent fresh water, without the difficulty of carrying it overland, which, in that hot climate, would have been very inconvenient. These pipes have been found as strong as iron ones of the same admeasurement. It is also applied to the coating of the wires of the Electric Telegraph with great advantage.