C 540 ] 
perforated with holes, thro’ which the fleam 
pafting produces a violent agitation in the wa- 
ter contained in the large boiler, and fo increafes 
the quantity of elaflic fleam. 
The flame of the fire (g) afeending up the chim- 
ney (bb) may in its paffage heat the water in 
the asolipoie (b). 
N.B. Either, or both, of the above contrivances may 
be applied to the boiler of an alembic, in the di- 
flillation of fea water for the ufe of navigators, in 
imitation of the method invented by the rev. Dr. 
Hales. 
Further Experiments relating to the Fire-engine , by 
lejjening the expences of cmfiruSling and working it. 
It is found by experiments, that, ccct. paribus , the 
elaflicity, or expanfive force of common air, is in 
proportion to its denfity. And alfo that cat. par. 
its elaflicity is proportional to its degree of heat. And 
therefore, that its elaflicity is proportional to its de- 
gree of heat, 
The fame probably holds true in other elaflic 
fluids ; and particularly in the fleam of water ; fince, 
like all other bodies, it is capable of rarefadlion (at 
leafl to a certain degree) by heat ; and its elaflicity, 
or expanfive force mufl augment in proportion to the 
degree of heat which it receives. 
