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by the attraction of the earth and the violent friction in 
the atmofphere, a ftrcng electricity and heat mud neceffa- 
rily be excited, by which means they are reduced to a 
flaming and melted condition, and great quantities of va¬ 
pour and different kinds of gafes are thus dilengaged, 
which did end the liquid mafs to a monflrous fize, till, 
by a (fill farther expanfion of thefe elaific fluids, they 
muff at length built. Dr. Chladni thinks alfo, that the 
greater part of the ffiooting-ftars are nothing elfe than 
fire-balls, which differ from the latter only in this, that 
their peculiarly great velocity carries them part the earth 
at a greater diitance, fo that they are not fo flrongly at¬ 
tracted by it as to fall down, and therefore in their paflage 
through the high regions of the atmofphere, occafion only 
a tranlient eleCtric fiafli, or actually take fire for a mo¬ 
ment, and are again fpeeuily extinguifhed, when they 
get to 1'uch a diitance from the earth that the air becomes 
too much rarefied for the exiltence of fire. 
The grounds on which profeffor Chladni founds the 
above theory, are farther explained by that author in the 
following manner: i. As fire-balls confift of denfe and 
heavy fubftances, which by their exceedingly quick move¬ 
ment, and the friCtion thence excited by the atmofphere, 
become eleCtric, are reduced to a ftate of ignition, and 
melted by the heat, fo that they extend to a great fize, 
and bui lt; it thence follows, that in places where frag¬ 
ments, produced by the burfting of a fire-ball, have been 
•found, fubftances endowed with all thefe properties mud 
alfo have been found. Iron, however, the principal com¬ 
ponent part of all the maffes hitherto found, poffeffes 
thefe properties in a very eminent degree. The weight 
and toughnefs of the principal component parts of fire¬ 
balls, which mult be very confiderable, lince, with the 
greateft poffible difienfion, they retain conli(fence enough 
to proceed with the utmolt velocity through fuch an im- 
menfe fpace without decompofition of their mafs, and 
without their progrefs being obftrnCted by the refinance 
of the air, agree perfectly well with melted iron ; their 
dazzling white light has by many obfervers been com¬ 
pared to that of melted iron ; iron alfo exhibits the fame 
appearances of flaming, fmoking, and throwing out fparks, 
and all thefe phenomena are molt beautiful when they 
take place in vital air. Of the extenfion by elaftic fluids 
expanded by the heat, and of the contraction which fol¬ 
lows from cold, traces may be difeovered in the internal 
fpongy nature of the iron maffes which have been found, 
and in the globular depreflions of the exterior hard cruft, 
the latter of which gives us reafon to fuppofe, that in 
thefe places there have been air-bubbles, which, on 
cooling, funk down. The mixture of fulphur found in 
various maffes, agrees alfo with the phenomena of fire¬ 
balls, and efpecially with the great inflammability of ful¬ 
phur in very thin impure air ; for it is well known that 
fulphur in ;fn air-pump will take fire in air in which few 
other bodies could do the fame. In regard to thofe maffes 
in which no fulphur was found, this may have arifen from 
the fulphur efcaping in vapour, fince fome time after the 
appearance of fire-balls a flrong fmell of fulphur has been 
-perceived. The brittlenefs of the Siberian iron mafs when 
heated, may arife from fome fmall remains of fulphur, 
which may perhaps be the caufe of the facility with which 
fragments of this mafs, as well as that found at Aix-la- 
Chapeiie, could be roafled. 
2. The whole texture of thefe maffes betrays evident 
figns of fufion. This, however, cannot have been ecca- 
fioned'bv any common natural or artificial fire; and par¬ 
ticularly for this reafon, becaufe iron fo malleable is not 
fufible in fuch fire, and, when it is fufed with the addi¬ 
tion of inflammable matters, lofes its malleability, and 
becomes like common raw-iron. The vitrified lubftanee 
in the Siberian mafs is equally incapable of being fufed 
in a common fire. The fire then mull have been much 
flronger than that produced by the common natural and 
artificial means, or the fufion mud have been effected by 
the force of exceedingly flrong electricity, or perhaps 
both caufes may have combined together. 
3. Befides the fimilarity of the above-mentioned maffes, 
the circumftances refpecting their falling.are fo like, that 
they cannot be confidered as merely accidental, and there¬ 
fore give more credibility to the accounts. This being 
premifed, the principal quellion then is, whether the phe¬ 
nomena of this kind obferved were the effects of thunder, 
or arofe from detached fragments of fire-balls > Several 
circumftances quoted by Dr. Chladni teem to oppofe the 
idea of their ariling from thunder ; but agree fo perfectly 
with every circumftance remarked in regard to fire-balls, 
that, without afi'erting any thing abfurd, every relation 
of this kind may, he fays, be admitted in their full and 
literal extent. In the atteftations refpeCting the iron 
mafs produced by a fire-ball which fell near Agram, it 
is mentioned that feveral people, in different parts of the 
kingdom, faw and obferved the burfting of the fire-ball, 
and heard its explofions and noife in the atmofphere, and 
perceived alfo that fontething fiery fell from the heavens, 
fo that it was a circumftance generally known in the 
neighbourhood, only that on account of the diftance it 
was not exaftly known in what place it had fallen. Hence 
it may be concluded, that it was no effeCt of lightning, 
hut an aftual fire-ball. Lightning, at a time of the year 
when dorms are not uncommon, would not have excited 
univerfal attention, much lefs would it have been ob¬ 
ferved at fuch a great diftance as a falling fiery mafs. From 
the fimilarity of thefe maffes, it is alfo highly improbable 
that, in all the places where they were found, fufible 
parts only fhould have been difeovered, and Humid have 
been changed in the fame manner by lightning, efpecially 
as in places ftruck by lightning no maffes of the like kind 
have been found, but always vitrified earthy particles. 
4. It is totally incomprehenfible how, on the high f]ate 
mountains, where the Siberian mafs was found, at a con¬ 
fiderable diftance from the iron mines ; in the chalky foil 
of the extenfive plains of America, where for a hundred 
miles around there are no iron mines, and not even fo 
much as a (lone to be-found; and at Aix-la-Chapelle, 
where, as far as the author knows, there are no iron 
works; fo many ferruginous particles could be collected 
in a fmall fpace, as would be neceffary to form maffes of 
1,600, 15,000, and 17,000, up to 33,600, pounds. .This 
circumftance fhews that thefe maffes could as little have 
been fufed by lightning, as by the burning of a foreft, or 
of foffile coal. Thefe malfes were found quite expofed 
and uncovered, and not at any great depth in the earth, 
where we can much more readily admit fuch an accumu¬ 
lation of ferruginous particles to have been melted by the 
effects of lightning. 
Should it be alked how fuch maffes originated, or by 
what means they were brought into fuch an infulatcd po- 
fition ; this queftion would be the fame as if it were alked 
how the planets originated. Whatever hypothefes we may 
form, we muft either admit that the planets, if we except 
the many revolutions which they may have undergone, 
either on or near their furface, have always been fince 
their firft formation, and ever will be, the fame ; or that 
nature, acting on created matter, poffeffes the power to 
produce worlds and whole fyftems, to deftroy them, and 
from their materials to form new ones. For the latter 
opinion there are, indeed, more grounds than for the for¬ 
mer, as alternations of deftruCtion and creation are exhi¬ 
bited by all organifed and unorganifed bodies on our 
earth-; which gives us reafon to fufpeCt that nature, to 
which greatnels and fmallnefs, confidered in general, are 
merely relative terms, can produce more efteCts of the 
fame kind on a larger feale. But many variations have 
been obferved on diftant bodies, which, in fome meafure, 
render the laft opinion probable. For example, the ap¬ 
pearing and total difappearing of certain liars, when they 
do not depend upon periodical changes. If we now ad¬ 
mit that planetary bodies have ftarted into exiftence, we 
cannot fuppofe that fuch an event can have otherwife 
taken place, than by conjecturing that either particles of 
matter, which were before difperfed throughout infinite 
fpace, in a more foft and chaotic condition, have united 
together 
