2 2 8 Dr. Bladen s Report 
j H <r it more manageable, being readily heated with the hand 
or°warm water, and cooled with cold water : and the very cir- 
cumftance, that fo much of the fluid was not required, proved 
a material convenience. The particular difadvantage in the 
method of weighing in a veffel, is the difficulty of filling it 
with extreme accuracy; but when the veflel is judi.ioufly and 
neatly marked, the error of filling will, with due re, be 
exceedingly minute. By feveral repetitions of the fame ex- 
periments, Mr. Gilpin feemed to bring it within the T rhi'l> 
part of the whole weight. 
The above-mentioned confiderations induced me, as well as 
the gentlemen employed in the experiments, to give the pre- 
ference to weighing the fluid itfelf ; and that was accordingly 
the method praflifed both by Dr. Dollfuss and Mr. Gilpin 
in their operations. 
The veflel chofen as moft convenient for the purpofe was a 
hollow glafs ball, terminating in a neck of a 1 mall bore. That 
which Dr. Dollfuss ufed held 5800 grains ot diftilled water, 
but as our balance was fo extremely accurate, it was thought 
. expedient, upon Mr. Gilpin’s repetition of the experiments, 
to ufe one of only 2965 grains capacity, as admitting the heat 
of any fluid contained in it to be more nicely determined. The 
ball of this veflel, which may be called the weighing-bottle, 
meafured about 2,8 inches in diameter, and was fpherical, except 
a flight flattening on the part oppofite to the neck, winch ferved 
as a bottom for it to ftand upon. Its neck was formed of a 
portion of a barometer tube, ,25 of an inch in bore, and about 
if inch long; it was perfectly cylindrical, and on its outfide, 
very near the middle of its length, a fine circle or ring was cut 
round it with a diamond, as the mark to which it was to be 
1 
