[ 3i6 ] 
^0 afcertain the true proportion there was in the two 
methods of diftilling, I put three gallons of water 
into the ftill ; and, when it boiled, put on the ifill- 
head, and fixed its nofe to the worm-tub pipe j which 
tub was full of cold water. When it had diftilled 
for an hour, the receiver was inftantly taken away. 
And on meafuring the diftilled water, found it to be 
two quarts and 45 cubic inches by a glafs divided 
into cubic inches. And a gallon containing 281 
cubic or folid inches, this quantity of diftilled wa- 
ter,. which was 186 cubic inches, is fth part of a 
gallon. 
f. Then, filling the ftill as full of water as beforeh- 
and when it began to boil, fixing the head to the 
ftill and worm-tub, which was Tull of cold water j 
there was diftilled in an hour, with conftantly blow- 
ing ihowers of frefh air up through the ftiliing Ik 
quors, five quarts, lefs by feven cubic inches, which 
is 34f.5ths cubic inches 5 that is, little lefs than the 
double of the -quantity, that is diftilled in the ufual 
way. In feveral other diftillations of a quart at a 
time, I found the quantity diftilled by ventilation to< 
be more than the double of that in the ufual way. 
So that the quantity by ventilation may, at a me- 
dium, be eftimated the double of the ufual diftilla- 
tion. It is the well known property of moving air, 
to carry along with it a confiderable quantity of ad- 
joining vapour, as allb of falling water to carry much 
air down along with it. 
6. It is to be hoped therefore, that fo confider- 
able an increafe in the quantity diftilled will be of 
gieat benefit to navigation, as it may be done in lefs 
time, and with lefs fire. 
7. In 
