[ 5«i ] 
and Reftdenee, he receives very little or no Benefit of 
the Air under his Chin or Bread, tho' never fo fit for 
Refpiration ; which Air neverthelefs in the lower parts 
of the Bell will remain cool a long time after he has 
been in the Bell, and with Difficulty drawn his Breath ; 
which cannot be denied, and is very obvious to any 
body who has been in a German Bagnio, and fuch as 
are made ufe of in this Country, where in a Angle 
Room all the Degrees of Heat are to be felt, by means 
of a Contrivance like Stairs to the very Top of the 
Ceiling, a Man when he places himfelf on the upper- 
mod Step will feel an exceffive Heat, fo that any 
body not very much ufed to it cannot endure the fame, 
nor draw his Breath, but will faint away 5 whereas on 
the firfly.fecond and third Steps from the Floor, the 
Heat is very moderate 5 nay, fometimes the Air near 
the Floor pretty cool, when at the fame time near 
the Ceiling the Heat of the fame is intolerable. I 
will not mention many other Indances I could pro- 
duce. 
To encounter this Inconvenience I have caufed a 
fpiral Tube of Copper, b, c. to be placed clofe to the 
Infide of the Bell, fo fixed that the fame may be 
taken out and cleanfed at Pleafure, and with Eafe$ 
and at the fame time not to incumber the Diver 
when he is in the Bell; at the upper end of this 
Tube b, a flexible Leather Tube is join'd two Foot 
long, at the End of which is a turn'd Ivory Mouths 
piece, which the Diver (as foon as he perceives the 
Air to grow hot in the Top of the Bell) keeps com 
ftantly in his Mouth, which he is able to do by means 
of the flexible Tube in whatever Pofture he is in* 
ftanding, fitting, bowing his Head ; $r. And all the. 
while 
