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Show ( I 78 ] VI. " Led by the Sage, Lo ! Britain's fons !hall guide Huge SEA-BALLOONS beneath the toiling tide ; I 96 The diving cafHes, roof' d with fpheric glafs, Ribb' d with {hong oak, and barr' d with bolts of brafs, Buoy' d with pure air iliall .endlefs tracks purfue, And PRIESTLEY's hand the vital flood renew.-- 200 Then fuall BRITANNIA rule the wealthy realms, Which Ocean's wide infatiate wave o' erw heltns ; Confine in netted bowers his fcaly flocks, . Part his blue plains, and people all his rocks. Led hy the Sage. I. 195· Dr. PriefUey's difcovery of the production of pure air from fuch variety of fubHances will probably foon be applied to the improvement of the divmg bell, as the fubfia.nces which contain vital air in immenfe quantities are of little value as manganefe and minium. See additional notes, No. XXXIII. In every hundred weight of minium there is combined about twelve pounds of pure air, now as fixty pounds of water are about a cubic foot, and as air is eight hundred times lighter th an water, five hundred weight of minium will produce eight hundred cubic feet of air, or about fix thoufand gallons. Now, as this is at leafl thrice as pure as atmofpheric air, a gallon of it may be fuppofed to ferve for three minutes refpiration for one man. At prefent the air can not be fet at liberty from minium by vitriolic acid without the application of fame heat, this is however very likely foon to be difcovered, and will then enable adventurers to journey beneath the ocean in large inverted fhips or diving balloons. Mr. Boyle relates, that Cornelius Drebelle contri ved not only a vefld to be rowed undeT water, but alfo a liquor to be carried in that veffel, which would fupply the want of freOt ai r. The veffel was made by order of J ames I. and carried twelve rowers befides paffengers. It was tried in the river T hames, and one of the perfons who was. in that fubmarine voyage told the particulars of the experiments to a perfon who related them. to Mr. Boyle. Annual regifter for 1774, p. 248. [ 179 ] Deep, in warm waves beneath the Line that roll, 2 o 5 Beneath the fhadowy ice-i:fles of the Pole, Onward, through bright meandering vales~ afar,. Obedient Sharks fhall trail her fceptred car, With harnefs' d necks the pearly flood difl:urb, Stretch the :Glk rein, and champ the filver curb; 21 o Pleafed round her triumph wondering Tritons play, And Sea-maids hail her on the watery way. -Oft fhall fhe weep beneath the cryfl:al waves 0' er fhipwreck' d lovers weltering in their graves ; Mingling in death the Brave and Good behold z I 5 ~ith :flaves to glory, and with flaves to gold ; Shrin'd in the deep .!hall DAY and SPALDING mourn, Each in his treacherous bell, fepulchral urn!- Day and Spalding mounz. I. '217· Mr. Day peri fh:d in~ diving bell, or diving _boat, f h . n . n · 100 at Plymo11th in June 1774, m whtch he was to have contmucd o tS own connr Uct , . for a wager twelve hours one hundred feet deep in water, and probably penfhed from his not poffe!Ii ng all the hydroHatic know~edge that was nece~ary. See note on Ulva, Vol. II. of this work . See Annual Reglfl:er for 1774, P· 24 .)· . . Mr. Spalding was profeffionally ingenious in the art of con~ruchng and managmg the diving bell, and had praClifeJ the bufi nefs many years wtth fuccefs. He we.nt · d by one of his young men twice to view the wreck of the Impenal down accompante . · · · 8 · E af\:-lndiaman at the Ki!h bank in Ireland. On defcendmg the thml ttme m June, 17 3, Aa 2 |