DIVING BELL. 



guage was rendered visible, and the depth 

 of the vessel under water ascertained by 

 a graduated line. 



An oar formed upon the principle of 

 the screw was fixed in the fore part of 

 the vessel ; its axis entered the vessel, 

 and being turned one way, rowed the 

 vessel forward, but being turned the 

 other way, rowed it backwards ; it was 

 made to be turned with the hand or foot. 



A rudder, hung on the hinder part of 

 the vessel, commanded it with the great- 

 est ease. The rudder was made very 

 elastic, and might be used for rowing 

 forward. Its tiller was within the vessel, 

 on the operator's right hand, fixed at a 

 right angle on an iron rod, which passed 

 through the side of the vessel ; the rod 

 had a crank on its outside, which com- 

 manded the rudder, by means of a rod 

 extending from the end of the crank to a 

 kind of tiller fixed on the left hand of the 

 ^rudder. Raising or depressing the first 

 mentioned tiller turned the rudder, as the 

 case required. 



A compass marked with phosphorus di- 

 rected the course both above and under 

 the water ; and a line and lead sounded 

 the depth when necessary. 



The internal shape of the vessel, in 

 every possible section of it, verged towards 

 an ellipsis as near as the design would al- 

 low ; but every horizontal section of it, 

 although elliptical, was as near to a circle 

 as could be admitted. The body of the 

 vessel was made exceedingly strong; 

 and to strengthen it as much as possible, 

 a Arm piece of wood was framed parallel 

 to the conjugate diameter, to prevent the 

 sides from yielding to the great pressure 

 of the incumbent water, in deep immer- 

 sions. This piece of wood was also a seat 

 for the operator. 



Every opening was well secured. The 

 pumps had two sets of valves. The aper- 

 ture at the bottom for admitting water 

 was covered with a plate perforated full 

 of holes, to receive the water, and pre- 

 vent any thing from choaking the pas- 

 sage, or stopping the valve from shutting. 

 The brass valve might likewise be forced 

 into its place by a screw, if necessary. 

 The air pipes had a kind of hollow sphere 

 fixed round the top of each, to secure the 

 air-pipe valves from injury : these hollow 

 spheres were perforated full of holes for 

 the passage of the air through the pipes : 

 within the air pipes were shutters to se- 

 cure them, should any accident happen to 

 the pipes or the valves on their tops. 



Wherever the external apparatus pass- 

 ed through the body of the vessel, the 



joints were round, and formed by brass 

 pipes, which were driven into the wood 

 of the vessel; the holes through the pipes 

 were very exactly made, and the iron 

 rods that passed through them were 

 turned in a lathe to fit them ; the joints ' 

 were also kept full of oil, to prevent rust 

 and leaking. Particular attention was 

 given, to bring every part necessary for 

 performing the operations, both within 

 and without the vessel, before the opera- 

 tor, and as conveniently as could be de- 

 vised ; so that every thing might be found 

 in the dark, except the water-gauge and 

 the compass, which were visible by the 

 light of the phosphorus, and nothing re- 

 quired the operator to turn to the right 

 hand or to the left, to perform any thing 

 necessary. 



The intended object of this vessel was 

 to destroy shipping, by the explosion of 

 a magazine of gunpowder. In the fore 

 part of the brim of the crown of the sub- 

 marine vessel was a socket, and an iron 

 tube passing through the socket; the tube 

 stood upright, and could slide up and 

 down in the socket six inches ; at the top 

 of the tube was a wood screw, fixed by 

 means of a rod, which passed through 

 the tube, and screwed \he wood screw 

 fast upon the top of the tube ; by push- 

 ing the wood screw up against the bot- 

 tom of a ship, and turning it at the same 

 time, it would enter the planks ; driving 

 would also answer the same purpose ; 

 when the wood screw was firmly fixed, 

 it could be cast oflf by unscrewing the 

 rod which fixed it upon the top of the 

 tube. 



Behind the submarine vessel was a 

 place above the rudder for carrying a 

 large powder magazine ; this was made 

 of two pieces of oak timber, large enough 

 when hollowed out to contain 150 pounds 

 of powder, with the apparatus used in 

 firing it, and was secured in its place by 

 a screw turned by the operator. A strong 

 piece of rope extended from the maga- 

 zine to the wood screw above mentioned, 

 and was fastened to both. When the 

 wood screw was fixed, and to be cut off 

 from its tube, the magazine was to be 

 cast off likewise by unscrewing it, leav- 

 ing it hanging to the wood screw ; it was 

 lighter than the water, that it might rise 

 up against the object, and apply itself 

 where fastened. 



Within the magazine was an apparatus, 

 constructed to ruiv any proposed length 

 of time under twelve hours ; when it had 

 run out its time, it unpinioned a strong 

 lock resembling a gwn-Jock, which gave 



