C 26 7 ] 
pofed into a kind of train, and confumed by a run- 
ning fire : for founds, as far as we know, are either 
produced by the quick and violent percuflions of hard 
bodies upon the air ; or by the fudden expanfion of 
an elaftic fluid, after being condenfed within fome 
folid fubftance. The noife occafioned by the motion 
of ele&rical matter is, perhaps, the only exception ; 
but we have no reafon to imagine, that this was at all 
concerned in the prefent cafe. There feems to be 
the more ground for believing this body was 
folid, at leaft that its furface was fo, from finding, 
that, after the violent explofion, it hill retained its 
form j a circumftance that could hardly take place, 
if the meteor had confided of nothing but vapours. 
We may therefore prefume, that the burning matter 
found vent through a hard cruft by certain apertures, 
which either might have been there invifible, or un- 
obferved. All I can fay in fupport of this conjecture 
is, that, by the Memoires of the Academy of Bo- 
logna, we find a meteor appeared in Italy in the year 
1715?, lower in the air than that we have now been 
treating of, and in which, it is pretended, four 
feveral chalms were diftinguifiied, each emitting 
fmoke *. To thefe arguments for the folidity of this 
body, we may add its extreme velocity, and the in- 
tenfity of the light ; which are likewife circumftances 
more conformable to a heavy and folid fubftance, 
than to one formed of exhalations only. 
Upon the whole, I believe it will appear, that: 
thefe relations are not favourable to the prevailing 
* /Ippareb ant in eo hiatus feu voragincs quatuor fumum exhalantes. 
Injiit . iff Acad. Bonon. Tom. I. p. 285. 
Mm2 hypo- 
