The Portland daily press. [volume] (Portland, Me.) 1862-1921, 1893-10-27


Ba1loon.-An Air Ship that can Stay
Af1oat a Month.
Prot. Hazen of the United States
weather bureau is going to make an aer-
ial voyage across the Atlantic after a
novel plan He will travel with balloon,
but it will be formed of strange material
and equipped with devices hitherto
unheard Of It will be directed by means
of propelIers and rudder, and is expect
ed to stay afloat two weeks or more,
though the trans-oceanic trip may re-
quire only fifty hours. The enterprise
will be paid for out of private funds,
but such instruments as, are required
for meteorological and other scientific
observations will be furnished by the
government.
The balloon will be small one, COM
paratively speaking Nearly every
aeronaut who has contemplated project
of this sort has supposed monster air
ship, holding from 200. 900 to 400, 900 cub
ic feet of sgas,sto! be requisite. a. Professor
Hazen considers such huge machine
unnecessary, and, on many grounds, an
desirable. 1t is enormously heavy, very
difficult to handle, almost impossible to
make sgas-light, and costs great sum
of money. He thinks that an envelope
containing 100. 900 cubic feet should be
plenty big enough for voyage to Europe
end if enough ..cash for the purchase of
such one cannot be got, the attempt
may be made in balloon of 80, 900 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 bal
looms 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 l per cent. day. The signal
Office has already purchased one of this
description. The material used is gold
beaters' skin, which is obtained from
part OF the intestines of the OK, called
the "caecum.n 1t is somewhat more cost
ly than cotton or ev. silk, but it is SUI
perior for the purposes in many ways.
The main point is that tight balloon
can be made of it, which is not practica;
BILE with any other substance hitherto
tried.
The gold beaters'. skin comes in small
sheets, the biggest obtainable being
twenty-five by ten inches Tt looks
somewhat like oiled tissu to the eye, but
it is not porous. Six layers put together
make about the thickness of letter paper
with nearly the same weight as silk.
However four thicknesses will serve for
a balloon, the sheets being overlaid
upon each other in such way that
there are no joints or seams. The first
step in the construction of the balloon is
to make a cloth bag of exactly the size
required, which is oiled and inflated.
Then the gold beaters skin is laid over
the outside of it, one thickness at time,
being made to adhere in manner which
is as yet a secret. Finally the cloth bag
is taken out and you have your balloon.
The Time Required.
The balloon will be filledswith hydrogen
which has a lifting power of 10 pounds
for each 1000 cubic feet. The bag con-
templated to hold 100000 cubic feet. will
thus have total lifting power of 1000
pounds. 1t is estimated. that. the whole
aerial machine, including the net, bas-
ket, drag rope, anchor, &C., will weigh
800 pounds. Three men will add a
weight of $50 pounds, and $50 pounds
more may be allowed for provisions and
water. This reckoning leaves d margin
of 5, 500 pounds, which would be taken
along as ballast in the shape of sand in
bags
The balloon ought not to lose more
than one-half of one per cent of gas in
twenty -four hours. If it lost as much
as one per cent, it would probably do
ten times as well as any other that has
ever been built in the United States. 1t
should keep afioat thirty days, whereas it
is likely that no balloon was ever made
in this country of it's weight. that would
stay in the air more than two days. How
ever, to make allowance for error, sup
pose that the loss of gas. was two per
cent. a day. This would amount to q,
600 cubic feet per diem, or $4,000 cubic
feet in fifteen days, supposing that 50
long time was required for the trans
atlantic voyage The machine could
afford to lose that much and yet get to
the other side omfortably.
On the other hand, the journey might
be accomplished in SO short time as
fifty hours, supposing that everything
went favorably. Speed could best be OBJ
tanned by travelling as high as 5000 feet,
because the currents at that elevation
are two or three times as fast as those
near the ocean. But at level SO far up
the gas has tendency to escape at the
neck Oh Gne Dag. In Ofder TO aVOlu JnaG
contingency Prof. Hazen intends to have
a smaller balloon hitched alongside of
the big one, the necks of the two being
joined together. When the hydrogen
flows out OF the neck of the larger bag
it will enter the little one and will not
be lost The sun shining, on balloon
heats it and causes the gas to expand, SO
that it is apt to escape at the neck.
Such misfortune is provided against
by the same device. The gas can be re-
turned to the big balloon by simply pull
ing down the small one.
To Select the Level.
At times it is desirable to keep at a
low level, when the high current is in
the wrong direction. To accomplish
this object Prof. King, the aeronauJ, has
suggested the use of drag rope, 5000
feet or SO in 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 weight
to hold it down. But Prof. Hazen does
not think favorab bly, of this idea, owing
to the fact that such rope would cause
serious retardation, if not absolute stop
page. His plan is to lower large bucket