PNEtJMATiCS.

call Cupping ; for when a Vacuum isa de by a Syringe in the Cupping-Glass

applied

i-el'V As the cold Air rusli’d into the Bell from the Bar-thf E otv, it expell’d the hot Air (which was lighter)\n, the Cock B, at the Top of the Bell, whichA; r ^ en open'd for that Purpose. By this Method,Hjj 1 * communicated so quick and in such Plenty,Ho doctor tells us, he himself was one of fivetli 0 together at the Bottom, in nine or ten Fa-

' v ith S '^ ater b f° r ^hove an Hour and an half at a Time,hq Ve ° ut any Sort of ill Consequence ; and he mightthi n Continued there, as long as he pleased, for anythat appeared to the contrary,genij S°‘ n g down, ’tis necessary it should be veryy at first, that the dense Air may be inspired toH t , .Ipi by its Spring, a Balance to the Pressure of, lr .in the BelL Upon each 12 Feet Descent, thebyi ls .ftopp’d, and the Water that enters is driven outthi s e j^ ln g >n three or four Barrels of fresh Air. Bytb e ^cans, the Doctor fays, he could (by taking offtage) Uy the Bottom of the Sea, just within theSh Q of the Bell, so far dry, as not to be overy s thereon.

ted LfT the Glass above so much Light was tranfmit-tvej, sten the Sun shone, and the Sea was clear andSr>d ’ that he could fee perfectly well to write and read,»k>d ^"tch more to take up any Thing under the Best ;lip the Return of the Air-Barrels, he could fendOf r y r s, written with an Iron Pen, on small Piecesto pj A directing they were to be moved from Place8. a n* .

8 ti(l. ut lf i dark Weather, when the Sea was roughhilt the^ 6 ^’ wou ld be as dark as Night in the Bell 3|il[> j the Doctor found he could keep a Candle burn-“y£v . Pell, as long as he pleased ; it being found'the ^eriment, that one Candle consumes much aboutQuantity of confined Air as one Man does,

ah

Ni. n

°tt a Gallon per Minute.

N

The

177