meafuring Heights with the Barometer. 715, 
difference doth exift between the elaftic force of dry and 
raoift air, I may be allowed hereafter to reafon by ana- 
logy, on the probable effects this will produce, in mea- 
furing heights with the barometer ; leaving it to others, 
much better qualified, to confider how far it will affeCt 
aftronomical refractions. In the following feCtion I 111 all 
therefore give an account of the barometrical obferva- 
tions made in Britain, and compare them with fome: 
others made in d iff ant countries. 
SECTION III. 
An account of the barometrical obfervations made in Bri- 
tain, wherein they are compared with fome others of the 
fame kind made in dijlant countries. 
THE revival of the inquiries into that curious and 
nfeful branch of philofophy, whereby vertical heights 
are determined to a great degree of exaCtnefs, by the 
preffure of the atmofphere alone, we owe to Mr. be luc ; 
who hath undoubtedly removed many of the difficulties 
that formerly occurred in the application of the barome- 
ter, and thereby encouraged others to attempt to over- 
come, fome part at ieaft, of fuch as remain. 
