fame late fiery Meteors. 2ne 
Windfor*, is very remarkable; but in general the accounts dif-. 
agreed fo much, that it would have been impoflible to conclude 
any thing from them. Perhaps too the method itfelf is lefs 
certain than has been thought; for as the propagation of found, 
and with intenfity too, in air rarefied 30000 times, prefents 
great difficulties in theory, though it may be in.fome meatfure 
explicable from the vaft bulk of the meteor, and the large 
quantity of this rare air it may therefore difplace by a fudden 
expanfion ;.I think it not improbable, that fome hitherto un- 
perceived circumftance comes into play, by which the whole 
effet may be modified: for inftance, if matter ‘belonging to: 
the meteor itfelf be what conveysthe found to our lewer atmo- 
fphere, it may either admit found to be propagated through. it: 
at a different rate than through common air, or it may move 
much fafter than found travels, as the entire meteor certainly 
does, and carry on the fonorific vibrations with it. Moreover,, 
we cannot be fure what is the velocity of found in air fo much 
rarer than where our experiments have been made. For thefe 
reafons, while we diftruft calculations of meteors founded on: 
the progrefs: of found, we fhould be particularly: careful-to note: 
down the intervals, and all the circumftances, as they may lead: 
to very curious difcoveries. The effect of the noife is,. fre- 
quently, to produce fuch-a fhaking of the doors, windows, and: 
the whole houfe, as is. miftaken for an earthquake. | 
Befides the report as of explofions which was heard afer the- 
‘meteor, another fort of found was faid to attend it, more: 
‘doubtful in its nature, and lefs eftablifhed by evidence ; I mean,, 
a kind of hifling, whizzing, or crackling, as it pafled along. 
That found fhould be conveyed to us in an inftant from a. body: 
above 50 miles diftant, appeaxs fo irreconcilable to all. we 
know of philofophy, that perhaps we fhould be juftified in: 
® See p, 144. of this volume, ; 
umputing. 
