544 Mr. Perkins on the progressive compression of 
of which this apparatus admitted was 1000 atmospheres ; 
being equal to 14,000 pounds to the square inch. 
In order to estimate ( though less accurately ) higher de- 
grees of compression, I had another piezometer, fig. 6, eight 
inches long, ground internally, perfectly cylindrical, and 
stopped at its upper extremity, with a flat disk of glass 
cemented into it. This tube I filled with water, and sub- 
jected it to a pressure of 2000 atmospheres. After repeating 
this experiment a great number of times, the average of the 
result showed that the column of water, 8 inches long, was 
compressed - of an inch, or f- part of its length. 
For the purpose of representing the law of condensation 
of water by different degrees of compressing force, I had a 
plate, 2, engraved, with parallel lines of of an inch a-part, to 
which the measure taken in each experiment was immediately 
transferred. 
After the results of 5 experiments had been thus laid down 
for every 10 atmospheres, as far as 1000, a curve line has been 
drawn through the mean of them, as near as could be done to 
preserve a regular curve line. It may readily be seen, that 
there are various irregularities observable ; but as the original 
records remain upon the plate, those who choose to theorize 
upon the subject, have the means of drawing any other curve 
that may suit their views of the true law of condensation. 
With the same apparatus, I also made experiments on the 
compression of other fluids. The most remarkable result I 
obtained was with concentrated acetic acid ; which, after 
compression with a force of 1100 atmospheres, was found to 
be beautifully crystallized, with the exception of about part 
of fluid, which, when poured out, was only slightly acid. 
