Evening star., 1925-07-26

y HEh.
onicial o. 8. Army Air Service Photo.
| to warrant further experiments with
the electric power system.
1t was the production of gasoline en-
gineS to supply the automobile de-
mand, toward the beginning of the
present century, that really made
aerial navigation practicable. In
France special gasoline engines were
| first attached to elongated gas bags
by the famous Brazilian aeronaut,
SantoS-D -Dumont. The development at
his personal expense progressed to the
point of proving practicability. after
| which the French government under
took the construction of larger and
more efficient airships of the non-rigid
type.
In the year 1900 Count Zeppelin, in
Germany. produced the first of the
rigid-frame airships. Failure of the
was no lack of confidence, with de.
termination to succeed, and each new
design showed satisfactory improve
ment over the preceding type.
In all. the Zeppelin Co. constructed
125 of those leviathans of the air
finally producing highly efficient air.
ships, one of which made a continuous
voyage during the war over Africa
and return, making $500 miles In four
days. and carrying 20 tons of mum.
ttons. These rigid-type airships are
from 900 to 700 feet in length and
nearly 80 feet in height.
England and America are the rivals
of Germany in the rigid airship com.
petition, although Germany still main.
tains the lead in size and flight per.
formance. The French confined their
attention to the smaller. non-rigid type
OF afrshfp. The Italians developed a
semi-rigid airship and are still devoted
to that type.
AS the name implies, It is a com.
promise between the non-rigid gas
bags. where the shape is maintained
solely by the pressure of the gas, and
the German invention of the com.
plete metal frame. Italy is the only
nation that has taken much interest
in the semi-1gid airship, although the
United States now has one sample
under construction, the size being
somewhat larger than is customary
for non-rigid airships.
The British utilized many of the
non-rigfd a1rships during the war, and
in addition thereto. shortly before the
armistice, they commenced construc-
ton Of few rigid-type airships, one
Of which. known as the R-34. crossed
the Atlantic Ocean both ways in July
1919.
The United States Jagged far behind
in airship development The Army
bought a small non-rigid airship in
1908. 1t was constructed by Capt
Tom Baldwin and propelled by the
first four-cylinder gasoline motor
made by Glenn Curtiss. About that
period there were similar airships
used for commercial exhibition pur
poses in this country. 1t was not
until the United States declared wal
against Germany that we began a
creditable interest in airship develop
ment.
During 1918 the United States
Navy constructed a number of the
small airships. primarily for the pur
pose of searching for enemy sub
marines and mines. At the same time
an engineering study of the rigid-type
a1rship was begpn, and resulted a few
years later In the excellent American
built airship. Shenandoah. The first
flight was made in August, 1923, but
the most important voyage was that
"one wild night" as the writer's des
ignated the thrilling encounter with 2
gale that tore the ship away from
its moorings at Lakehurst, n. J., ir
January of this year.
The stanchness of the construction
together with skill of the navtgatine
personnel, brought the Shenandoah
back to the hangar in spite of a seri
ously damaged bow. Whatever the
cost for repairs, the expenditure is
well worth the price by proving be
yond question the structural safety OF
American-built rigid airships wher
inflated with helium gas
THE mooring tower for airships
was developed by the British as a
necessity during the war, but 1t also
will play a most important part in
commercial applications of airshir
transportation hereafter. Without
moortng towers each rigid airship re
quires large and expensive hangar
for shelter and several hundred mer
to hold and maneuver it when it de
scends at its landing field. Strong
winds made airship landings difficult
and often caused damage to the en-
gine cars suspended below the hull.
Military airship stations are usually
provided with plenty Of soldiers fol-
maneuvering ships out and in hangers
but for strictly commercial service the
cost for ground personnel would be
prohibitive.
hydrogen gas is highly inflammabIe
and directly responsible for the de
struction of number Of airships OF
various sizes with loss of many val
liable lives. Next below hydrogen in
ascensional force there is helium gas
1t is not combustible: in fact, 1t is alb
solutely inert, and in laboratory ex
per1ments cannot be made to combine
chemically with any other element.
The few cubic feet Of helium In
| chemical laboratories previous to 1917
| cost between $1,000 and 81 1000 Der
cubic foot. Modern warfare laws trfb
ute to all the sciences, and in this par
tcular application American chemists
and physicists accounted for their
task most admirably by devising
means Of separating helium from
natural gas at cost Of about cents
| for q cubic foot. The helium produc
| ton development was. and still is, in
| the charge of the Bureau of Mines
using funds supplied equally from
Army and Navy appropriations.
| Since the war helium research has
continued, until now the cost is only
Gems rci c@bic foot,