Submarine Appliances And Their Uses
Deep Sea Diving, &c., &c.

Fulton's In 1800, the American, Robert Fulton, who was the first man to introduce steam naviga- Submarine . Vessel. tion on the rivers of his native country, made a vessel to enable men to explore the sea bottom. Fulton gave a demonstration with his vessel in the Seine before some members of the French Government, Payerne's But probably the first really practicable diving boat was that made by a Frenchman, Submarine ta n „ , .. . . .........„ , Vessel. 1 ay erne, in 1844. This scientist had long studied the question, but his chief difficulty lay in supplying the occupants of such a boat with fresh air. In 1844, however, he came to the conclusion that it was quite practicable, by chemical means, to restore the purity of the air in the boat without recourse to the atmosphere, and he ultimately built a vessel on this principle, which was employed in the French Government works at Cherbourg. I ig. 93 gives a diagram representing the general construction of this machine. It was formed of strong iron plates riveted together in the form shown, with the internal partitions constructed in the same way. A manhole (A) gave entrance to the machine at the top, the cover to which was securely fastened before de- scending. Light was admitted through strong glass lenses or bull’s eyes (N N) inserted in the upper portion of each side of the machine- Mooring rings (O O) were securely fastened at either end, and an iron frame (D) was erected over the manhole (A), on which a pulley could be affixed to facilitate the removal of heavy materials when the machine was at the surface. Fig. 93. Internally, the machine was divided into five air-tight and water-tight compartments ; the chamber (L) in which the pumps and other requisites for the general management of the machine were placed ; the working chamber (P), open at the bottom of the water, and in which the man engaged in the subaqueous work la- boured; the ballast chamber (C), in which was placed some 36 tons of iron ballast; and the two air reservoirs or chambers (B B), in which air was compressed by pumping previous to the descent of the machine. A manhole (M) was provided between the chambers (L) and (P), which was securely fastened before opening the manhole (A) on the arrival of the machine at the surface, and was kept open when the men were at work at the bottom. When occasion required, the plates (M M) could also be re- moved, so as to give more room for conducting the work. Manholes (Q Q) were also provided between the chambers (L) and (B B), to admit of entry to the latter for cleaning and repairs. The machine was about 43ft- long and 10ft. in depth, and had a total weight of 62 tons, including the ballast and the weights (K K), which weighed together 4 tons, and were used for lowering to the bottom, so as to allow the machine to rise if, in descending, it 169