AEROSTATION. 
weigh lefs than before; and, confidering that the folid 
contents of veifels increafe in much greater proportion 
than their furfaces, he fuppofed that a metalline velfel 
might be made fo large, that, when emptied of its air, it 
would be able not only to raife itfelf in the atmofphere, 
but to carry up paffengers along with it; and he made a 
number of calculations necelfary for putting the projeft 
in execution. But, though the theory was here unexcep¬ 
tionable, the means propofed were certainly infufficient to 
accomplifh the end : for a velfel of copper, made fo thin 
as was necelfary to make it float in the atmofphere, would 
be utterly unable to re lift the external pretfure; w'hich 
being demonltrated by thofe (killed in mechanics, no at¬ 
tempt was made on that principle. 
In the year 1709, however, as we Were informed by a let¬ 
ter publifiled in France in 1784, a Portuguefe projector, 
Friar Gufman, applied to the king for encouragement to 
his invention of a flying machine. The principle on 
which this was conllrufted, if indeed it had any princi¬ 
ple, feems to have been that of the paper kite. The 
machine was conllrufted in form of a bird, and contained 
feveral tubes through which the wind was to pafs, in or¬ 
der to fill a kind of fails, which were to elevate it; and, 
when the wind was deficient, the fame effect was to be 
performed by means of bellows concealed within the body 
of the machine. The afcent was alfo to be promoted by 
the eleftric attraction of pieces of amber placed in the 
top, and by two fpheres inclofing magnets in the lame 
fituation. 
Thefe childifh inventions fhew the low date of fcience 
at that time in Portugal, efpecially as the king, in order 
to encourage him to farther exertions in Inch an ufeful in¬ 
vention, granted him the firft vacant place in his college 
of Barcelos or Santarem, with the firft: profelforihip in 
the univerlity of Coimbra, and an annual penlion of 600,000 
reis during his life. Of this De Gufman, it is alfo related, 
that, in the year 1736, he made a wicker balket of about 
feven or eight feet diameter, and covered with paper, 
which railed itfelf about 200 feet in the air, and the ef¬ 
fect was generally attributed to witchcraft. 
In the year 1766, Mr. Henry Cavendilh afcertained the 
weight and other properties of inflammable air, determi¬ 
ning it to be at leaf! leven times lighter than common air. 
Soon after which, it occurred to Dr. Black, that, per¬ 
haps a thin bag filled with inflammable air might be buoy¬ 
ed up by the common atmofphere; and he thought of 
having the allantois of a calf prepared for this purpofe : 
but his other avocations prevented him from profecuting 
the experiment. The fame thought occurred fome years 
afterwards to Mr. Cavallo ; and he has the honour of be¬ 
ing the firll: who made experiments on the fubjeft. He 
firft tried bladders; but the thinned of thefe, however 
well fcraped and prepared, were found too heavy. He 
then tried Chinefe paper; but that proved fo permeable, 
that the vapour palled through it like water through a 
fieve. His experiments, therefore, made in the year 1782, 
proceeded no farther than blowing up foap-bubbles with 
inflammable air, which afcended rapidly to the cieling, 
and broke againlt it. 
But while thedifcovery of the art of aerolfation feemed 
thus on the point of being made in Britain, it was all at 
once announced in France, and that from a quarter whence 
nothing of the kind was to have been expected. Two 
brothers, Stephen and John Montgolfier, natives of An- 
nonay, and mailers of a confiderable paper-manufaftory 
there, had turned their thoughts towards this projeft as 
early as the middle of the year 1782. The idea w-as firft 
fuggefled by the natural afcent of the fmoke and clouds in 
the atmofphere ; and their delign was to form an artificial 
cloud, by inclofing the fmoke in a bag, and making it 
carry Up the covering along with it. Towards the middle 
of November that year, the experiment was made at 
Avignon, with a fine filk bag of a paralleiopiped lhape. 
By applying burning paper to the lower aperture, the air 
was rarefied, and the bag afcended in the atmofphere, and 
Vol. I. No. 11. 
165 
llruck rapidly againfl the cieling. On repeating the ex¬ 
periment in the open air, it rofe to the height of about 
leventy feet. 
An experiment on a more enlarged fcale was now pro¬ 
jected; and a new machine, containing about 650 cubic 
feet, was made, which broke the cords that confined it, 
and rofe to the height of about 600 feet. Another of 
thirty-five feet in diameter rofe about 1000 feet high, and 
fell to the ground three quarters of a mile from the place 
where it afcended. A public exhibition was next made 
on the fifth of June, 1783, at Annonay, where a vaft num¬ 
ber of fpeftators allembled. Animmenfe bag of linen, 
lined with paper, and containing upwards of 23,000 cubic 
feet, was found to have a power of lifting about ^oolbs. 
including its own weight. The operation was begun by 
burning chopped draw and wool under the aperture of the 
machine, which immediately began to fwell; and after 
being fet at liberty afcended into the atmofphere. In ten 
minutes it had afcended 6000 feet; and, when its force 
was exhaufted, it fell to the ground at the difiance of 766S 
feet from the place from whence it let out. 
Soon after this, one of the brothers arrived at Paris, 
where he was invited by the academy of fciencesto repeat 
his experiments at their expence. In confequence of 
this invitation, he conllrufted, in a garden in the Faux- 
botirg of St. Germain, a large balloon of an elliptical 
form. In a preliminary experiment, this machine lifted 
up from the ground eight perfons who held it, and would 
have carried them all off if more had not immediately 
come to their alliftance. Next day the experiment was re¬ 
peated in prefence of the members of the academy; the 
machine was filled by the combultion of fifty pounds of 
ftraw made up in fmall bundles, upon which about twelve 
pounds of chopped wool were thrown at intervals. The 
ufual fuccefs attended this exhibition. The machine foon 
fwelled; endeavoured to afcend; and immediately after 
luftained itfelf in the air, together with the charge of be¬ 
tween 400 and 500 pounds weight. It was evident that it 
would have afcended to a great height; but, as it was de- 
ligned to repeat the experiment before the king and royal 
family at Verfailles, the cords by whicli it was tied down 
were not cut. But, in confequence of a violent rain and 
wind which happened at this time, the machine was fo far 
damaged, that it became necelfary to prepare a new one 
for the time that it had been determined to honour the 
experiment with the royal prefence ; and fuch expedition 
was tiled, that this valf machine, of near llxty feet in 
height, and forty-three in diameter, was made, painted with 
water-colours both within and without, and finely deco¬ 
rated, in no more than four days and four nights. Along 
with this machine was fent a wicker-cage, containing a 
Iheep, a cock, and a duck, w'hich were the firft animals 
ever fent through the atmofphere. The full fuccefs of 
the experiment was prevented by a violent guft of wind 
which tore the cloth in two places near the top before it 
afcended. However, it rofe to the height of 1440 feet; 
and, after remaining in the air about eight minutes, fell 
to the ground at the diftance of 10,200 feet from the place 
of its letting out. The animals were not in the lealt hurt. 
The great power of thefe aerolcatic machines, and their 
very gradual defeent in falling to the ground, had origi¬ 
nally fnewed that they were capable of tranfporting peo¬ 
ple through the air with all imaginable fafety ; and this 
was further confirmed by the experiment already men¬ 
tioned. As M. Montgolfier, therefore, propofed to make 
a new aeroftatic machine of a firmer and better conftruc- 
tion than the former, M. Filatre de Rozier offeredhimfelf 
to be the firft aerial adventurer. 
This new machine was conllrufted in a garden in the 
Fauxbourg of St. Antoine. It was of an oval lhape, 
about forty-eight feet in diameter, and feventy-four in 
height; elegantly painted on the outlide with the lignsof. 
the zodiac, cyphers of the king’s name, and other orna¬ 
ments. A proper gallery, grate, See. were appended in 
the manner afterwards defcribed; fo that it was eafy for 
U u the 
