50 Prof. Beck on the Influence of Pressure 
chains which raise the vessel and the frame upon which it is sup- 
ported. By forcing water, ora mixture of alcohol and water, 
(used in winter,) into the cylinder, the piston is forced outward, 
and thus the vessel, with necessary machinery, is brought to the 
required height. 
During the month of December, 1834, a curious fact was no- 
ticed in regard to one of these presses, by Mr. Ring, the super- 
intendent of the establishment, who had the kindness to apprise 
me of the occurrence, and to furnish me with all the particulars. 
I have delayed the publication, in the hope that some additional 
information might be obtained. But this expectation has not 
been realized, and I now send you the following note, nearly in 
the form in which it was prepared about eight years since. 
On Saturday, the 13th of December, 1834, the ship Orleans, 
of six hundred tons admeasurement, was bide’ out of the water 
by means of two hydraulic presses, each of which contained a 
column of liquid, (common whiskey,) fourteen feet in length, 
and fourteen inches in diameter. Mr. Ring supposed that after 
making the proper allowance for friction, each press must have 
raised three hundred tons. The thermometer during the day 
ranged at about 40° F. A change in the weather occurred on 
Sunday, and on Monday, the 15th, the mercury fell as low as 7° 
F. On Tuesday, the 16th, when the presses were examined, it 
was found that in one of them the ram had been forced outward 
one inch and three quarters, raising with it the ship, and the cra- 
dle, which weighed about one hundred tons. 
The following are the exact dimensions of the ipicnsstins in 
which this change was observed. 
Length of the eylindet, eA the 17 feet, 10 ee 
Diameter, - - oi vabas? tf 
_ Length of enchants of sis, ee 
Diameter, = - - ds Shen Dain 
Entire length of — ae jie 16 hal det 
Diameter, - - - + ofS cheat 
Weight of the eylieso, . 16 tons, 5 cwt. 
As the effect above described, was at once supposed to be due 
to the reduction of temperature which had taken place, the engi- 
neer was directed to make a moderate fire on each side of the 
cylinder throughout its whole length. Under this treatment the 
ram soon commenced a retrograde movement, which continued 
