[ 37p ] 
contain'd in an Air Barrel, lower'd down a Fathom 
deeper than the. Bell, without opening the Cock for 
difcharging the hot Air ; the Water would, by the 
Accefs of the Air out of the Barrel, be quite, or to a 
very fmall Matter, expell'd out of the Bell * and when 
the fame was again lower'd down five Fathom more, 
the fame Operation with another Air Barrel repeated, 
and the Bell afterwards haul'd up, it was no fmall 
matter of Delight to fee, that every Fathom the Bell 
came up, it would difcharge itfelf of the fuper- 
fluous and large Quantity of Air, which came up from 
the Bottom of the Bell in very large Bubbles, as big 
as Eggs of an OJirich ; which Difcharge of Air and 
Phenomenon continued, till the Equilibrium of the 
Air in the Bell, and Preffure of the Water, was re- 
ftor'd, and till the Bell came above the Surface of the 
Water. 
At other Times I have obferved, when no Air was 
by the way taken into the Bell, but the fame lower'd 
down the common Way, and haul'd up again after 
fome Time, that the very Inftant when the Bell fhould 
part with the Surface of the Water, the Strength of 
two Men more was required at the Capfton at that 
Time, than before and after the Bell hung freely in 
the Air 5 from whence I prefume it plainly appears, 
that the Air which palfcs thro' the Lungs of a living 
Creature, lofes its Elafticity, and that the Lungs of a 
Man make a kind of a Vacuum in the Bell 5 for which 
Reafon the Diver feels at the very Inftant, when the 
Bell parts with the Water, a very fmart Prelfure in his 
Ears. 
Tho' Experience thus has taught me, that no In- 
vention is more fafe and ufeful than the Campana, 
C c c 2 Urinatoria v 
