4 i 6 M. -de luc’s Barometrical Obfervations on 
■ t - r ^ ~ * r r ** r ••• . 
Rave doors at the entrance of each gallery, and fome- 
times many of them one after an other, without which it 
would not be poflible to keep any lamps lighted in 
thefe fubtdrraneous regions. 
It is probably to this conftant renewal of the air, that 
the miners of Ramelfberg are- indebted for the good 
health they enjoy, notwithffcanding the prodigious heat 
they feel while they are at work, and the quantity of ful- 
phur which exhales ; from every part; and it is likewife 
probably from this caufe that my barometrical obferva- 
tions gave me the heights more exactly than I could 
have expected from thefe circumftances. The following 
are the refults of thefe obfervations, the particulars of 
which you likewife have fubjoined. 
Height 
I’entree de toutes les galeries; et quelquefois meme plufleurs de fuite; fans quoi 
il ne feroit pas poflible de tenir les lampes allumees dans ces fouterrains. 
C’eft fans doute a ce renouvellement continuel de Pair, que les mineurs du 
Ramelfberg doivent la bonne fante dont ils jouiflent, malgre la chaleur prodi- 
gieufe qu’ils eprouvent pendant le terns de leur travail, et la quantite de fouffre 
qui s’exhale de toute part: et c’efl: aufli probablement la caufe, de ce que mes 
obfervations du Barometre, me donnerent les hauteurs, plus exa<Aement que je 
ne l’attendois d’apres ces circonftances. Void, Monfleur, les refultats de ces 
obfervations, dont vous avez aufli les details ci-joint. 
Hauteur 
