AEROSTATION. 
grand sight before them, Mr. Garnerin cut 
the rope, and in an instant he was separated 
from the balloon, trusting his safety to the 
parachute. At first, viz. before the para- 
chute opened, he fell with great velocity ; 
but as soon as the parachute was expanded, 
which took place a few moments after, the 
descent became very gentle and gradual. 
A remarkable circumstance was observed ; 
namely, that the parachute, with the appen- 
dage of cords and basket, soon began to vi- 
brate like the pendulum of a clock, and the 
vibrations were so great, that more than 
once the parachute, and the basket with Mr. 
Garnerin, seemed to be on the same level, 
or quite horizontal : however, the extent of 
the vibrations diminished as he descended. 
On coming to the earth, Mr. Garnerin ex- 
perienced some pretty strong shocks; but 
he soon recovered his spirits, and remained 
without any material hurt. As soon as the 
parachute was separated from the balloon, 
the latter ascended with great rapidity, and, 
being of an oval form, turned itself with its 
longer axis into an horizontal position. 
We now come to the practice of the art. 
The shape of the balloon is one of the first 
objects of consideration. As a sphere ad- 
mits the greatest capacity under the least 
surface, the spherical figure, or that which 
approaches nearest to it, has been generally 
preferred. However, since bodies of this 
form oppose a greater surface to the air, and 
consequently a greater obstruction to the 
action of the oar or wings than those of some 
other form, and therefore cannot be so well 
guided in a calm, or in a course different 
from the direction of the wind, it has been 
proposed to construct balloons of a conical 
or oblong figure, and to make them proceed 
with their narrow end forward. Next to 
the shape, it is necessary to consider the 
stuff that is most proper for forming the en- 
velope of the inflammable or rarefied air. 
Silk stuftj especially that which is called 
lutestring, properly varnished, has been most 
commonly used for hydrogen gas balloons : 
and common linen, lined within and without 
with paper, varnished, for those of rarefied 
air. Varnished paper, or gold beater’s skin, 
will answer the purpose for making small 
hydrogen gas balloons ; and the small rare- 
fied air balloons may be made of paper, 
without any varnish or other preparation. 
The stuff for large balloons of both kinds re- 
quires some previous preparation. The best 
mode of preparing the cloth for a machine 
upon Montgolfier’s principle, is first to soak 
it in a solution of sal-ammoniac and size, 
using one pound of each to every gallon of 
water ; and when the cloth is quite dry, to 
paint it over with some earthy colour, and 
strong size or glue. It maybe also varnished 
over when perfectly dry, with some stiff, 
oily varnish, or simple drying linseed oil, 
which would dry before it penetrates quite 
through the cloth. The pieces of which an 
hydrogen gas balloon is to be formed must 
be cut of a proper size, according to the 
proposed dimensions of it, when the varnish 
is sufficiently dry. The pieces that com- 
pose the surface of the balloon are like those 
gores that form the superficies of a globe : 
and the best method of cutting them is to 
describe a pattern of wood or stiff card-pa- 
per, and to cut the silk or stuff upon it. To 
the upper part of the balloon there must be 
adapted a valve, opening inward, to which 
is annexed a string passing through a hole 
made in a small round piece of wood, which 
is fastened to the lowest part of the balloon, 
opposite to the valve, to the boat below it ; 
so that the aeronaut may open it as occasion 
requires, and let the hydrogen gas out of the 
balloon. To the lower part of the balloon 
are fixed two pipes of the same stuff with 
the covering, six inches in diameter for a 
balloon of 30 feet, and much larger for bal- 
loons of greater size, and long enough to 
reach the boat. These pipes are the aper- 
tures through which the hydrogen gas is in- 
troduced into the balloon. The boat may 
be made of wicker work, and covered with 
leather, well painted or varnished over. The 
best method of suspending it is by means 
of ropes, proceeding from the net which 
goes over the balloon. This net should be 
formed to the shape of the balloon, and fall 
down to the middle of it, and have various 
cords proceeding from it to the circum- 
ference of a circle, about two feet below 
the balloon; and from that circle other ropes 
should go to the edge of the boat. This 
circle may be made of wood, or of several 
pieces of slender cane bound together. The 
meshes of the net may be small at top, 
against which part of the balloon the hydro- 
gen gas exerts the greatest force, and in- 
crease in size as they recede from the top. 
A hoop has been sometimes put round the 
middle of the balloon for fastening the 
net. This is not absolutely necessary ; but 
when used, it is best made of pieces of cane 
bound together, and covered with leather. 
When the balloon and its appendages are 
constructed, the next object of importance 
is to procure proper materials for filling it. 
Hydrogen gas for balloons may be obtained 
