44° Appendix to Dr. Blag den's Report 
in future for shortness call 1,5, and which it is evident must 
be applied with the sign + or — to the quantity of expan- 
sion or contraction read off from above or below o, as the case 
may require. They were then cooled down to 30° of tem- 
perature, when the spirit in the long instrument was found 
to stand 165, and that in the short instrument 163,5 below o. 
They were again brought to the temperature of 6 o°, when the 
spirit in the long instrument was found to stand 0,5, below o* 
and in the short instrument 1,5 above o as before. They were 
then heated to ioo°, when the spirit in the long instrument 
stood at 231, and in the short instrument at 233,5 above o. 
I brought them again to the temperature of 6o°, when the 
spirit in the long instrument was found to stand 3 below o, 
but in the short instrument 1,5 above o as before. 
It appears from these experiments, that the contraction of the 
spirit, by the long instrument, for 30 degrees, that is, in cooling- 
down from 6o° to 30°, is 165 ; but in heating it up again to 6o°, 
it was found not to stand at o, as before, but 0,5 below ; there- 
fore the expansion will be only 164,5, the mean is 164,75. 
The expansion, on heating up from 6o° to ioo°, will be 
231 + 0.5 = 231,5; but on cooling down from ioo° to 6o° 
again, the spirit was found to sink 3 below o, therefore it will 
be 231 + 3= 234 ; the mean 232,75, and the total expansion, 
from 30° to ioo°= 397 >5 ; differing from ours, in defect, by 
0,05 of a division. But the two methods of heating from 
6o° to ioo°, and cooling from ioo° to 6o° again, differ 2,5 di-. 
visions, or so many ten thousandth parts of the whole. 
The contraction from 6o° to 30°, by the short instrument, 
appears to be 163,5+ 1,5 = 165, and the expansion, on heating 
