APPENDIX. 349 
prcffurc or Cold. What Effeft fiich an ex- 
tream Preffure as two or three Miles depth 
of Sea Water would have on it, we can 
know only by Experience j which might 
probably be tried in the manner here propo- 
fed without much Difficulty. 
27. The greateft Degree of Compreflurc 
that I have been able to give Air was in the 
following manner, viz. Having in frofty 
Weather placed the abovementioned Bomb 
with the mercurial Gage in it under the Cy- 
der Prefs in the (ame manner as before deferib- 
cd,I then covered the Bomb with a large Qiian- , 
tity of pounded Ice, which had half its 
Quantity of common Salt mixed with it: ‘In 
a little time this great Degree of Cold burft 
the Bomb into three Pieces, from Top to 
Bottom ; thefe Pieces opened wide, by fal- 
ling afunder, but their lower Parts touched 
each other ; an evident Proof that the Wa- 
ter, though compreffed to Co great a Degree, 
as to burft the Bomb, yet had very little Elaf* 
ticity in it. 
28. The Bomb was lined all over within 
fide with a Shell of Ice which was about :|ths 
Inch thick, it was full of Air Bubbles. 
ip. As 
