. ( 494 ) 
the Eyes Blood-flior, and frequently to occafion fpitting 
of Blood. 
When therefore there has been occafion to continue 
long at the Bottom , fbme have contrived double flexible 
PippS, to circulate Air down into a Cavity enclofing the 
Viver as with Armour, to bear off this preffure of the 
Water, and to give leave to his Bread to dilate upon In - 
fpiration : the frelh Air being forced down by one of the 
Pipes with Bellowes or otherwife, and returning by the 
other of them; riot unlike to an Artery and Vein. This 
has indeed been found fufficient for fmall Depths, not ex- 
ceeding twelve or fifteen Foot : but when the Depth fur- 
pafles three Fathoms, Experience teaches us that this 
Method becpmes impracticable: for though the Pipes 
and ttye reft of the Apparatus may be contrived to perform 
their Office duly, yet the Water, its weight being now 
become considerable, docs lo clofely embrace and clafp 
the Limbs that are bare, or covered with a flexible Cove- 
sing, that iij obdruCts the Circulation of the Blood in 
them ; and prefles with fq much force on all the Jun- 
ctures, whero the Armour made tight vyith Leather 
Skins or fuch like, that if there be the lead defeCHn any 
of them, the whole Engine will indantly fill with Water, 
which will rulh in with fb much violence, as to endanger 
the Life of the. Man below, who may be drown’d before 
he can be drawn, qp Upon both, which accounts, the 
danger encreafes, with the Depth. Belides a Man thus 
fhut up in a weighty Cafe, as this mud needs be, cannot 
hut be very unwieldy and una&ive, and therefore unfit 
to execute what he is defigned to do at the Bottom. 
To remedy thefe Inconveniences, the Diving-Btll was 
next thought of; wherein the Diver is fafely conveyed 
into any reasonable Depth, and may day more or lefs 
titpe under Water , according, as the Bell is of greater or 
le&r Capacity, This is mod conveniently made in form 
of 
