Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-10-21

terprise will be paid for out Of private
funds. but such instruments as are re-
CURED for meteorological and other scien-
tihc observations will be furnished by the
government.
The balloon will be a small one, compare
lively speaking. Nearly every aeronaut
who has contemplated project of this sort
has supposed monster air ship, holding
from 100000 to 400. 900 cubic feet OF gas to
be requisite. Professor Hazen considers
such a huge machine unnecessary, and, on
many grounds, undesirable. 1t is enormous
~ heavy, very difficult to handle
almost impossible to make gas
tight, and costs great sum Of money. He
thinks that an envelope containing 100, 900
cubic feet should be plenty big enough for a
voyage to Europe, and II enough cash for
the purchase of such a one cannot be got,
the attempt may be made in a balloon of
$4,000 cubic feet.
Gold Beaters' Skin.
The chief difficulty met with in aerial
voyages is leakage of gas. But science has
recently learned how to construct balloons
that will not leak. At all events such gas
bags are now made in Europe which lose
gas only at the rate Of one-half of 1 per
cent day. The signal office has already
purchased one Of this description. The ma
obtained from a part Of the intestines of
the OK, called the "caecum." 1t Is some
what more costly than cotton or even silk
put 1t Is superior for the purpose in many
ways. The main point is that a tight bal
loon can be made Of 1t. which is not prac-
tried
The gold beaters skin comes in small
two by ten inches. 1t looks somewhat like
oiieo tissue to the eye. but Is not porous Six
layers put together make about the thick
ness OF letter paper, with nearly the same
weight as SILK. However, four thicknesses
VIII serve for balloon, the sheets being
overlaid upon each other in such a way
tnat there are no joints or seams. The first
soep IN the construction Of the balloon is
70 make cloth bag of exactly the size re-
CURED, which is oiled and inflated. Then
the gold beaters skin Is laid over the ont
sloe OF It, one thickness at time, being
made to adhere in a manner which 10 aS vat
secret. Finally, the cloth bag ia t.Lan
OUT and you have your balloon.
The Time Required.
Inc balloon will be filled with hvdroosn
"hlch mas lifting power of 10 pounds for
each i'ooo cubic feet. The bag CONTEMPLATED
u hoio loo,OOO cubic feet, will thus have a
totai nftins power Of 1000 pounds. IT ia
estimated that the whole aerial machine
ihciuolnG fhe net, basket drag rope. anchor
&c, Wal Neigh $40 pounds. Three men win
auu weight OF $50 pounds, and $50 pounds
more may De allowed for provisions and
water. Inis reckoning leaves a margin OF
o'ooV pounds which would be taken along a
ballast In the shape Of sand In bags
me paloon ought not to lose more than
Sne-hau OF one per cent of gas in twenty
TOUR nours:-.nit lost much as one ner
cent, 1t would probably do ten times 10 Nj,
as any other that has ever been built in the
United states. 1t should keep afioat thirty
Jays Jay whereas 1t is likely that no balloon
m 10 in lie
that would stay in the air more than two
oays. however, to make allowance for
error, suppose that the loss of gas was two
per cent day. This would amount to 1000
CUBIC rect per diem. or 10000 cubic feet in
hfteen days, supposing that SO long a time
was required for the transatlantic VOYAGE
The machine could afford to lose thar much
and yet get to the other side comfortably.
ON the other hand, the journey might be
accomplished in short a time as fiftv
hours, supposing that everything went fav
orably. Speed could best be obtained bv
travelling as high as 5000 feet because the
currents at that elevation are two or three
times as fast as those near the ocean Rnt
at level so far up the gas has a tendency
to escape at the neck of the bag In order
to avoid that contingency, Prof. Hazen in
tends to have smaller balloon hitched
alongside of the big one, the necks of the
two being Joined together. When the hydro
gen flows out of the neck of the larger ba q
1t Will enter the little one and will not be
q
and causes the gas to expand. so that it is
apt to escape at the neck. Such a misfortune
Is provided against by the same device. The
gas can be returned to the big balloon by
simply pulling down the small one.
To Select the Level.
At times 1t is desirable to keep at a low
level, when the high current is in the
wrong direction. To accomplish this object
Prof. King, the aeronaut. has suggested
ha Of droo
length. AS the bag receives an impulse to
rise from the expansion of the hydrogen
within it the rope is lifted out of the water
and serves as a weight to hold 1t down.
But Prof. HaZen does not think favorably
of this idea, owing to the fact that such a
rope would cause serious retardation, If not
absolute stoppage. His plan is to lower a
large bucket from the basket near the sea-
This could be filled with water by means
of small pail as fast as weight might be
required to hold the balloon down. The big
bucket could readily be emptied from the
car when desired by opening a valve in its
bottom.
1t is most important that the aeronaut
should be able to place his balloon at any
level of the atmosphere he pleases. OF
course, the currents of air at various ele-
vations commonly flow in different direc-
tons. There may be an unfavorable wind
at 1000 feet, and at the same time just the
right breeze may blow at 10000 feet. The
currents at the latter altitude are always
blowing from west to east across the Allan
tic and for that reason there should be no
difficulty in accomplishing the trip quickly
Prof Hazen thinks of taking with him a
small pilot balloon, which may be run I'D
to the height of mile above the great gas
bag so as to ascertain the direction of the
breeze at a higher level without taking the
trouble to ascend in order to find out
Rudder and PrOpellers.
1t is proposed to employ means Of sim
pie nature for directing and propelling the
balloon. There will be no complicated ma
chinery, but merely a rudder and propel-
lers The latter will be worked by man
power. very likely by the feet, bicycle
fashion. Probably the propeller shaft will
be made to project both ways, having a
screw in front and a screw behind. thus
getting double power and incidentally pre-
serving the balance. The problem of pro-
pe:ling balloons has already been solved to
some extent. In France such air ships have
succeeded in travelling in the teeth of
fifteen-mile wind. All that is needed for
the purpose is the proper mechanism, and
experiments in that direction are being
made
1t is too early to say from what point the
start for Europe will be made. Very likely
1t will be made from New York, but some
Charleston. Making the departure from
a place so far down the coast would render
the chance better for reaching England,
owing to the fact that the storms of the
Atlantic tend northward. However IL the
directing machinery works prODerly. IL does