Evening star. [volume] (Washington, D.C.) 1854-1972, 1908-07-31
Gas Slowly Pouring Into the
Baldwin DirigibIe.
HYDROGEN IS BEING USED
Superiority to the Ordinary City
Illuminant.
No Two Can Be Built That Will
Work Exactly Alike-Interest
Of Treasury officials.

OF treasury OWc16!S.
Gasmaking for the Baldwin dirigible
began early this morning. and by the
time The Star readers are looking over
this the big bag will be about quarter
full and still rising. 1t will take nearly
forty eight hours to do the infioating, for
this work with hydrogen is much slower
than with city gas that comes through a
big main under pressure calculated to
run the consumers gas bills up out of
all proportion to the illumination they
get. The big 5O,OOO-foot army balloon
can be inflated at the gas works in about
four hours, but although the dirigible
holds only 1900 feet, 1t will take two
days for the work.
Generating the Gas.
The generator that is being used at
Fort Myer is more or less like five big
churns, made of oak with hoops on
them. A ton of iron filings is distributed
between them and sulphuric acid and
water. In the proportion of five to one,
Is poured in. The gas comes out of the
last washing tank into hose made of
balloon fabric and is led into the balloon
house, where it connects with the inlet
valve of the bag One can barely see
the big gray silk bag swelling under its
netting. but the steady flow of gas keeps
up. and at least one man is kept busy
all the time walking around the bag and
shifting the little ballast bags that are
hooked into the netting to keep the main
gas bag from getting up into the roof
of the house.
To the lay mind the flying of balloon
Is probably simple matter. What is
easier than to hitch a gas pipe to the
bag and let her fill? But that is not the
way 1t works out. The big bag is laid
out A@ the floor and the balloon net care
fully spread over it. Then around the
edge there are scores of small sand bags
weighing about thirty-five pounds each.
These have iron hooks on the upper edge.
and as the gas comes in and the bag fills
the hooks are caught into the balloon
netting and the gas bag allowed to rise.
There are fifty of these sand bags on
side to the 10O-foot dirigibIe. and it is
one mans work to keep shifting the hooks
In the netting. The silk and the netting
both have to be kept smooth and not too
tight. and the netting must not be al
lowed to slip on the gas bag, else the
imitation is faulty and the car will not
hang right from the net There are tricks
in all trades. and one of them is balloon
filling. By the way. if you go over to
Fort Myer these days leave your pipe at
home There is a big mo Smoking"
sign on the front of the balloon house,
for there is already enough hydrogen in
post if it should be accidentally ignited.
Ideal Shape for Balloon.
1t has been stated that the Baldwin
dirigibe carries out the lines of Prof,
Zahm's models. shaped with a view to
getting the least skin resistance from
the wind. This is only partly true. DR..
Zahm found in a series of interesting ex-
periments that the ideal shape for a diri-
gible balloon bag was that of very
broad-shouldered. sharp-tailed fish. Gu
riously enough. there is less resistance
when the blunt end of the model is point
ed to the wind than when the sharp end
is forward. The Baldwin balloon is built
on this theory. but the difference in size
Of the two ends of the bag is very slight.
There has to be almost equal lifting power
on each end, and the ideal shape has to
be sacrificed for practical considera tons.
Differences in Propellers.
There is a rather clumsy-lookng pro-
peller that will be used with the ship,
while a lighter an dmuch more elegant
looking one is lying on the scrap heap.
This is another point about airships that
no man can calculate in advance. The
proof Of propeller is in the working,
and no two propellers can be built that
will work exactly alike. Capt. Baldwin
says that two prOpellers may be built of
the same weight and pitch and apparent
ly as alike as man can make them, but in
practice one may have 10 or 20 per cent
more efficiency than the other. Thus 1t is
that the heavier and the worse looking
propeller is to be used on the ship. This
is only carrying to a greater extreme
what has been found true In the construc-
ton of steamship propellers from torpedo
boats to ocean liners. The same model
rarely gives the same efficiency even
when cast from the same mold.
There is nothing much left to do at the
fort now but sit down and wait for the
big gasbag to fill. Capt Baldwin says
that he does not calculate on losing more
than 1 per cent Of hydrogen a day from
leakage. He Is in favor of using hydro
gen for balloon. and airships owing to its
great lifting power compared with illumi-
mating gas. This enables one to do a
much greater amount of practical work
with much smaller gasbag, which is an
advantage In transportation, handling and
lessening wind resistance.
Although the United States government
has been slow to take up the balloon and
aeroplane for army purposes. the prob
craft in other directions is not being
overlooked. The carrying out of tenta :
tive plan to connect several large eastern
cities by an aerial transportation line will
depend largely on the success OF capt.
Baldwin's flights in his dirigible.
Possibilities for Smugglers.
One of the interested spectators at the
| trials will be Beekman Winthrop, assist
ant secretary of the Treasury, who is
directly in charge of the customs service.
At the present time the customs service
depends upon the revenue cutter service
to patrol the coast and prevent smuggling
| of goods. but that>t the customs officials are
giving consideration to the exigencies
which may arise If aeroplanes become
available in the Illegal importation OF
goods is evidenced by the interest they
are taking in the efforts Of the army to
make a great stride in aerial invention.
while we have not had occasion as yet
to deal with a case of smuggling by
means of aerial craft" observed Assistant
Secretary Winthrop today, land while the
use of airships for such a purpose exists
only in fiction, it Is essential that we look
into the future. 1 am going to make every
| effort to be present at the Fort Myer
tests. and l think they will be exceedingly
interesting especially the trials of the