L 
Royal Society. 305 
coal-fmoak ^ there are three fuch fires on the fame hills that are 
extinguifhed in the fummer, bur burn in the winter 5 the rea- 
Ion of which the Dodor judged to be thus, that the bowels of 
the earth being cooler in the fummer than in the winter, do 
not fend forth that quantity of thofe fubtilc exhalations, as may 
be fufficient to maintain a flame in fummer ^ but in winter the 
bowels of the earth being hotter, which is evident by the 
fmoaking of fprings in winter and not in fun\mer, and from the 
experience of miners, when greater plenty of ileams are fent 
forth, which are agitated in the air into a flame, the brifk motion 
of the parts, one againft another, being promoted by the fubtility 
and briflc agitation of the aerial particles, that mutually affift 
each other. 
A neia Lamp 5 hy 2)r. Rob. St. Clair. Phil. Tranf. N° 245. 
p. 380. 
ET a lamp, made two or three inches deep, with a pipe 
coming from the bottom, almoft as high as the top of the 
veflel, be filled firft with water, fo high as to cover the hole of 
the pipe at the bottom, to the end the oil may not get in at 
the pipe, and fo be loft 5 then let the oil be poured in, fo as to 
fill the veffel almoft brim-full, which muft have a cover 
pierced with fo many holes as there are defigned to be wicks 5 
when the veffel is thus filled, and the -wicks are lighted, if 
water fall in by drops at the pipe, it will keep the oil always at 
the fame height, or very near it, the weight of water to that of 
oil being, according to Klrcher's table, as 20 if is to 19, which 
in two or three inches will make no confiderable difference; if 
the water runs fafter than the oil waftes, it will only run over at 
the top of the pipe 3 what does tiot run over, will come under 
the oil, and keep it to the fame height. 
Experiments about Freezings hy M. Des Mafters. Phil, 
Tranf. N° 245. p. 584. 
A Tube off of an inch diameter, being filled with water to 
the height of 2 inches, and fet to freeze in a mixture of 
fnow and fair, the water when perfedly frozen, appeared i|: of 
an inch above the ma.rk it ftood at before freezing : Another 
tube of almoft an inch diameter, being ^Jled with water 
to the height- of 6 inches, and fet to freeze as before, rofe 
I of an inch above the mark ; the water made ufe of, was a 
ibrt of rough pump water, which, according to what trials 
had been made with it, did, upon the efFufion of oil of tartar 
Vol. III. Q.q ^'' 
