EXISTENCE OF ICE AT HIGH TEMPERATURES. 
129 
at B. The connexion at B was made tight by fine copper 
wire. The tube DE was about one inch in diameter, and about 
four feet long from the bend to the end E ; after connexion 
with C it was completely filled with mercury, care being taken 
to expel the air from A, C, and DE as completely as possible ; 
the whole was then inverted over the mercurial trough E, as 
Fig. 1.* 
shown in the figure, when the mercury fell to o, the ordinary 
height of the barometer. The mercury was run out of A by 
tilting up the bottle and inclining the tube DE. By this means a 
Torricellian vacuum was obtained from A to o. DE was next 
brought to the vertical, and the bottle A placed in the trough P. 
A tin bottle Gr without a bottom was fitted with a cork, so that 
it might slide somewhat stiffly along DE. 
* For the use of this and the following figures we are indebted to the 
kindness of the President of the Royal Society. 
NEW SERIES, VOL. V. NO. XVIII. 
K 
