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dually : if lie admitted too much, 1 e ejected as much as was ne-cessary to obtain ail equilibrium by the two brass forcing-pumpsplaced at each hand. Whenever the vessel leaked, or he wouldascend to the surface, ho also made use of these forcing-pumps.When the skilful operator had obtained an equilibrium, lie couldrow upward or downward, or continue at any particular depth,with an oar placed near the top of the vessel, formed upon theprinciple of the screw, the axis of the oar entering the vessel; byturning the oar one way he raised the vessel, by turning it theother way he depressed it. A glass lube eighteen inches long,and one inch in diameter, standing upright, its upper end closed,and its lower end which was open, screwed into a brass pipe,through which the external w ater hud a passage into the glass tube,served as a water-gauge or barometer. There was a piece of cork,with phosphorus on it, put into the water-gauge. W hen the ves-sel descended the water rose in the water-gauge, condensing theair within, and hearing the cork, with its phosphorus, on its sur-face. By the light of the phosphorus the ascent of the water inthe gauge was rendered visible, and the depth of the vessel underwater ascertained by' a graduated line. An oar, formed upon theprinciple of the screw, was fixed in the fore-part of the vessel; itsaxis entered the vessel, and being turned one way', rowed the ves-sel forward, but being turned tbe other wav rowed it backward;it was made to be turned by the hand or foot. A rudder, hungto the hinder part of the vessel, commanded it with the greatestease. The rudder was made very' elastic, and might be used forrowing forward. Its tiller was w ithin the vessel, at the operator’sright-hand, fixed at a right angle, on an iron rod which passedthrough the side of the vessel ; the rod had a crank on its outsideend, which commanded the rudder, by means of a rod extendingfrom the end of the crank to a kind of tiller, fixed upon the lefthand of the rudder, liaising and depressing the first-mentioned, tiller, turned the rudder as the case required. A compass mark-ed w ith phosphorus directed the course, above and under the wa-ter: and a line and lead sounded the depth when necessary.Every opening was well secured. The pumps had two sets ofvalves. The aperture at the bottom, for admitting water, was co-vered with a plate, perforated full of holes to receive the water,and prevent any thing from choking the passage, or stopping thevalve from shutting. 'Die brass valve might likewise be forcedinto its place with a screw, if necessary. The air-pipes had a kindof hollow’ sphere, fixed round the top of each, to secure the air-pipe valves from injury : these hollow spheres were perforated fullof holes for the passage of the air through the pipes:within the air-pipes were shutters to secure them, shouldany accident happen to the pipes or the valves on their tops.Wherever the external apparatus passed through the body of thevessel, the joints were round, and formed by brass pipes, whichwere driven into the wood of the vessel ; the holes through thepipes were exactly made, and the iron rods, which passed throughthem, were turned into a lathe to fit them ; the joints were alsokept full of oil, to prevent rust and leaking. Particular attentionwas given to bring every part, necessary for performing the ope-rations, both within and’ without the vessel, before the operator,and as conveniently as could be devised ; so that every thinganight he..found in the dark, except the water-gauge and the com-pass, which were visible by the light of the phosphorus; and no-thing required the operator to turn to the right hand, or to the lell,to perform anv thing necessary. The design of this submarinevessel was to convey a magazine, and its appendages, to the bot-tom of a ship to effect its destruction. In the fore-part of thebrim of the crown of the submarine vessel were a socket, and aniron tube passing through the socket: the iron tube stood uprightand could slide up and down in the .socket six inches: at the topof the tube -was a wood screw, fixed by means of a rod, whichpassed through the lube, and screwed the wood-screw fast uponthe top of the tube.: by pushing the wood-screw up against thebottom of a ship, and turning it at the same time, it would enterthe planks ; driving would also answer the same purpose: whenthe wood-screw w as firmly fixed it could he cast olf by unscrew-ing the rod, which fastened it upon the top of the tube. Behindthe submarine vessel was a place, above the rudder, for carryinga large powder-magazine ; this was made of two pieces of oaktimber, large enough, when hollow ed out, to contain 150 poundsof powder, w ith the apparatus used in firing it, and was securedin its place by a screw, turned by the operator. A strong piece

of rope extended from the magazine to the wood-screw above-mentioned, and was fastened to both. When the wood-screw wasfixed, and to be cast oft from its tube, the magazine was to he castoff likewise by unscrewing it, leaving it hanging to the wood-screw ; it was fighter than the water, that it might rise up againstthe object to which the wood-screw and itself were fastened.Within the magazine was an apparatus, constructed to run anyproposed length of time: it unpinioned a strong lock resemblinga gun-lock, w hich gave fire to the powder. This apparatus wasso pinioned that it could not possibly move till, by casting off themagazine from the vessel, it was set in motion. The skilful ope-rator could swim so low on the surface of the water as to approachvery near a ship in the night, without fear of being discovered ;and might, if he chose, approach the stem or stern above waterwith very Ijftle danger. He could sink very quickly, and keep atany depth he pleased, and row a great distance in any direction hedesired, without coming to the surface ; and when he rose to thesurface, he could soon obtain a fresh supply of air, when, if neces-sary, he might descend again, and pursue his course. The fol-lowing experiments were made to prove the use of this vessel.The first experiment was made with about two ounces of gun-powder, which were exploded four feet under water, to prove tosome of the hrst personages in Connecticut , that powder wouldtake fire under water. The second experiment was made withtwo pounds of powder, inclosed in a wooden bottle, and fixed un-der a hogshead, with a two-inch oak plank between the hogsheadand the powder ; the hogshead was loaded with stones as deep asit could swim ; ;a wooden pipe descending through the lower headof the hogshead, and through the plank, into the powder contain-ed in the bottle, was primed with poivdei. A match put to thepriming, exploded the powder; which produced a very greateffect, rending the plank into pieces, demolishing the hogshead,ami casting the stones and. the ruins of the hogshead, with a bodyof water, many feet into the air, to the astonishment of the spec-tators. There were afterwards made many experiments of a simi-lar nature, some of them with large quantities ot powder; they allproduced very violent explosions, much more than sufficient forthe purpose proposed. After various attempts to find an operatorto his wish, Mr. Bushnell sent one, who appeared more expertthan the resi, from Hew York to a litty-gun ship, lying not farfrom Governor’s Island . lie went under the ship, and attemptedto fix the wood-screw into her bottom; but struck, as he sup-poses, a bar of iron, which passes from the rudder-hinge, and isspiked under the ship’s quarter. Had lie moved a few inches,which he might have done without rowing, he would probablyhave found wood where he might have fixed the screw ; or, if.theship were sheathed with copper, lie might easily have pierced it:but not being well skilled in the mam qvment of the vessel, in at-tempting to move to another place, he lost the ship; alter seekingher in vain, for some time, he rowed some distance, and r.ose tothe surface of the water, but found day-light had advanced so far,that he diust not renew the attempt. The adventurer said that hecould easily have fastened the magazine under the stem of theship, above water, as lie rowt ‘ a the stern, and touched it be-fore lie descended. Had he tastened it there, the explosion of150 pounds of powder (the quantity contained in the magazine),must have been fatal to tilt* ship. In his return from the -ship toNew York he passed near Governor’s Island , and thought lie wasdiscovered by the enemy on the island ; being in haste to avoidthe danger lie feared, he cast olf the magazine, as he imagined itretarded him in the swell, which was very considerable. Alterthe magazine had been east off one hour, the time the internal ap-paratus was set to run, it blew up with great violence Severalother machines have been constructed for the purpose of divingsall of them depending on the same principles.

DIVINITY.. See Theology.

DIVIO, DIBIO, or DIVIONENSE CASTKUM, in an-cient geography, a town of the I.ingones, in Gallia Belgica, nowcalled Dijon . v

DIVISIBILITY, in physics, is that property by which theparticles of matter in all bodies are capable ot a separation or dis-union from each other. The Peripatetics and Cartesians holddivisibility to he an affection of all matter. The Epicureans ,again, allow it to agree to every physical continuum ; hut theydeny that this affection agrees to all bodies, for the nrimary cor-puscles or atoms they maintain to be perfectly iusecable aim indi-visible.