the Depth of the Mines in the Hartz. 445 
Sindic leyser obferved the barometer at his houfe at 
Claufthal, in the morning and at noon; when inftead of 
falling, as at Oder-brucke, it rofe half a line, and re- 
mained at that point till the evening. The only caufe to 
which I can afcribe this difference between his obferva- 
tion and mine, is the increafe of heat in his room : but 
there was no obfervation with the thermometer to correct 
the effeft of this caufe; I fhall therefore content myfelf 
with my own obfervation for this meafure, though I 
employ Mr. leyser’s for the following one. 
M. le Sindic leyser obferva le barometre chez lui a Claufthal le matin et 
a midi: et au lieu de baiffer, comme a Oder-brucke, il monta de § ligne, et 
refta a ce point jufqu’au foir. Je ne faurois attribuer cette difference entre 1’ob- 
fervation de M. leyser et la mienne, qu’a ce que la chaleur augmenta dans la 
^chambre: mais il n’y eut point d’obfervation du thermometre pour corriger 
Feffet de cette caufe. Je m’en tiens done a mon obfervation feule pour cette 
mefure-ci; quoique j’employe celle deM. leyser pour la fuivante* 
A midi 
