45° Appendix to Dr. Blagden's Report 
It appears from the above experiments, that the contraction 
of the spirit from 6 o° to 30° is 161 -j- 4 = 165, and the expan- 
sion in heating up again to 6o°, the same. On heating up 
from 6 o° to ioo°, 23 6 — 4 = 232, and therefore the total ex- 
pansion from 30° to ioo° is 397 ; but in cooling down from 
ioo° to 30°, the total expansion will be 236 -{- 162 = 398 ; 
the former quantity differs 0,55, in defect, and the latter 
0,45 of a division, in excess, from the experiments by weight. 
Now it is evident that the method of heating up from 30° to 
ioo° can only be admitted as giving a true result, for it was 
found on cooling the spirit down from ioo° to 30°, that the 
contraction from 6 o° to 30° had been increased by 1 ; so much 
of the fluid being left behind in the upper part of the two 
tubes, as appears on its being heated up again to 6o°, for then 
it stood lower in the two tubes by 1 than it did before ; care 
having been taken that the upper part of the two tubes 
should be as dry as possible before the experiment commenced, 
for which purpose the instrument was charged over night, 
and constantly kept in a vertical position. It must also be 
obvious that 397, which was found for the total expansion in 
heating up from 30° to ioo°, must likewise be too great by 
nearly the same quantity, it having been cooled down from 
6o° to 30° previous to its being heated up to ioo°, as this 
would tend to make it sink so much lower than it would have 
done in the first instance had that not been the case. 
After the above experiments, the spirit was poured out, and, 
previous to the repetition of the foregoing experiments on a fu- 
ture day, it was charged with more of the same spirit which 
was used in the former experiments, and the instrument was 
hung up as before. 
