DIVING BELL. 



pressure, and the sleeves from being 

 thrust into the engine ; d d represents a 

 cover to fit the head of the engine, fas- 

 tened down with screws, and leather be- 

 tween the borders, so as to prevent leak- 

 ing in any depth of water ; a b repre- 

 sents a plate of lead, to be fastened be- 

 fore the engine, in a straight line, pass- 

 ing between the arms, not only as a pro- 

 per weight to sink the engine, but as a 

 balance thereto ; whereby the diver will 

 always be kept in a proper posture for 

 working, and the more so by means of a 

 block, or cradle, supposed to be fasten- 

 ed over the lead, by which means the 

 diver has not only the power of handling 

 what is at the bottom, but may at any 

 time rest his arms from work ; g is the 

 engine-rope, by which it is let down and 

 hauled up again from the bottom ; z y u 

 is called the life-line, with a knot at y, so 

 as the handle at r may always remain at 

 a due distance for the diver to take hold 

 thereof, in order to give any notice to 

 the persons above, as, by agreement, by 

 giving a certain number of pulls, or sud- 

 den twitches, which is immediately felt 

 by the person that holds the line. The 

 diver can tarry under water at least half 

 an hour at one time, without the help of 

 pipes, or any other air than what the en- 

 gine contains. At and v> are two brass 

 screw caps, or plugs, both which are to 

 be opened as soon as the diver gets from 

 the bottom to the water's surface, in or- 

 der to give him fresh air by help of a 

 pair of bellows blowing at the latter; at 

 which, when the engine leaks, we like- 

 wise pump out the water. In deep wa- 

 ter the diver is forced to make use of a 

 saddle on his back, with a ridge touching 

 the upper part of the engine, whereby 

 he can keep his arms at a due distance 

 out of the engine, which otherwise 

 would be thrust in by the column of wa- 

 ter pressing thereon equal to the weight 

 thereof. 



The subject of submarine navigation 

 was largely and pleasantly descanted 

 upon by Mcrsennus, ia his " Tractatus 

 de Magnetis Proprietatibus," and Bishop 

 Wilkins has given a chapter at some 

 length on the subject, in his " Mathe- 

 matical Magick," (ed. 1648) where he 

 affirms that Cornelius Dreble has proved, 

 beyond all question, that the contrivance 

 is feasible, by the experiments he made 

 in England. The chapter of Wilkins is 

 entertaining, for a sort of visionary facili- 

 ty with which he removes the difficul- 

 ties, and enumerates the benefits, of 

 these submarine enterprises. For let- 



ting out and taking in such things as the 

 nature of the voyage may require, he 

 recommends bags, or flexible tubes, 

 somewhat resembling the scupper bags 

 of ships. The progressive motion may, 

 he observes, be produced by fins or 

 oars, which will operate with ease when 

 the vessel is truly equipoised; and if 

 swiftness should not be obtained, he sup- 

 poses the observations and discoveries 

 to be made at the bottom of the sea 

 would abundantly recompence for the 

 defect. The greatest difficulty, in his 

 apprehension, would be, the necessity of 

 renovating the air for respiration and 

 combustion; for remedying which, be- 

 sides the probability that custom may 

 render men capable of living in air of in- 

 ferior purity, he has several philosophi- 

 cal views and projects. The conveni- 

 ences and advantages he enumerates arc, 

 1. Privacy ; as a man may thus go to any 

 part of the world invisibly, without being 

 discovered or prevented. 2. Safety from 

 the uncertainty of tides and tempests 

 that vex the surface ; from pirates and 

 robbers ; and from the ices that so much 

 endanger other voyages towards the 

 pole*. 3. It may be of use to undermine 

 and blow up a navy of enemies : 4. Or 

 to relieve a blockaded place. 5. And as 

 the prospect enlarges in the mind of our 

 author, he proceeds to contemplate the 

 unspeakable benefit of submarine disco- 

 veries. Experiments on the ascent and 

 descent of submerged bodies; the ex- 

 ploration of the deep caverns and pass- 

 ages, and the waters of the ocean ; ob- 

 servations on the nature and kinds of 

 fishes, with allurements, artifices, and 

 treacheries, which may successfully be 

 practised during so familiar a residence 

 in their territories ; the food and oil they 

 may afford the probability of fresh 

 springs for a supply of water at the bot- 

 tom of the sea ; the facility of recovering 

 submarine treasures, whether lost or na- 

 turally produced beneath the ocean ; and 

 last of all he adds, that 



" All kinds of arts and manufactures 

 may be exercised in this vessel. The. 

 observations made by it may be both 

 written, and, if need were, printed here 

 likewise. Several colonies may thus in- 

 habit, having their children born and 

 bred up without the knowledge of land, 

 who could not chuse but be amazed 

 with strange conceits upon the discovery 

 of this upper world." 



The only modern instance of actual 

 submarine navigation is that of Mr. Bush- 

 n el, recorded in the Transactions of the 



