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

Fig. No. 85. The cylinder girded to the loins, serves for the purpose of comp .ng air within it, by means of the piston " T " worked by rackwÎrkSthuf P the specific gravity of the diver so that he can ascend or go down at will. John Lethbridge, a Devonshire .nan, in the year I7,5 contrived “ a vention*":— g PerSOn'” The fO11OWing iS °™ account Necessity is the parent of invention, and being, in the year ,7tS quite reduced ff ' " r‘f‘‘ a""ly' my th0UghtS ,Umd «P°n «>”•<> extraordinary method Io re- <.< my misfortunes, and was prepossessed that it might be practicable to contrive a „me ine o recover wrecks lost in the sea. The first step ! took towards it was To- g into a hogshead (upon land), bunged up tight, where I stayed half an hour, without Cin lh'i'"bl“ "”' " T 1 lle" 1 made “ trencl1 near “ at ,he bottom of my orchard this place, in order to convey a sufficient quantity of water to cover the hogshead tl Öl'' d lmZ1 cmM Uve under °' i, and I found I could stay longer under -water than upon land. This experiment being tried, J then began to think of making my engine wuc, was soon made by a cooper, in Stanhope Street, London, of which I give you thejollowing description It is made of wainscot, perfectly rounded, about 6 feet in length, about feet diameter at the head, and about 18 inches dia- meter al the foot. It is hooped with iron hoops, without and within, to guard against pressure. There are two holes for the arms, and. a glass about 4 inches diameter and t| inches thick to look through, which is fixed on the bottom part, so as to be m a direct line with the eye. Two air-holes upon Ilie upper part, into one of which air is conveyed by a pair of bellows, both which are stopped with plugs immediately before going down to the bottom. At the fool part there is a hole to let out water some- times. There is a large rope fixed to the back or upper part, by which it is let down, and. there, is a little line, called the signal line, with which the people above are directed what to do, and under is fixed a piece of tim- ber, as a guard, for the glass. .1 go m with my feet foremost, and when my arms are got through the holes then the head, is put on, which is fastened with screws. 1 lie straight, upon my breast, all the time I am in the engine, which hath been many times more than two hours, being fre- quently refreshed upon Ilie surface by a pair of bellows. * I can move about 12 feet square al the bottom, where I have staid many times thirty-four minutes. 1 have been >o fathoms deep many a hundred times, and have been 12 fathoms, but with great difficulty. . Mr. Symons came to the Lizard to see my engine, which he liked, so well that he desired to adventure with me on some wrecks near Plymouth, where we adventured together without success. increasing watertight of his in- 161