Evening star. [volume] (Washington, D.C.) 1854-1972, 1907-10-07
PROBLEMS FOR AERoNAUTs.
Conquest of Contrary Currents Of the
Air the Question.

BERLIN. October THE science OF
aerial navigation, at least in Germany,
mas reached a point where many of the
most prominent investigators are asking
themselves In which direction they shall
pursue their experiments. The problem
OF steering is satisfactorily solved, but
there remains the important question Of
tho conquest of the contrary currents of
the air. and this raises the issues be-
tween the advocates of Fighter than the
air. and heavier than the air."
Balloons inflated with gas are gener-
ally regarded here as having nearly, IL
not quite attained the final stage of
their possibilities. which, as is commended
although marvellous in comparison with
the position of only five years ago, still
leaves much to be achieved before the
air can be said to be mastered.
All three systems-the rigid, the semi
rigid and the flexible - represented, re-
spectively, by the Siderable balloons Of
Count Zeppelin, the German army aero
nauts and Maj. Won Parseval-have been
and still are being tested.
All have given evidence of the fact that
in light winds and otherwise favorable
weather they may be steered and maneu-
vered with great facility. Not one of
them. however, has on any occasion ven-
tured into the air when a strong wind
was blowing. for the good reason that
their SleerSnen are aware tnat their weak
motive power would not permit progress
sion.
The greatest speed attained by any OF
them, and this applies also to French
balloons. has not exceeded in round fig
ures twenty-eight miles an hour, and at
that rate in such a wind they would be
driven backward. Even the Zeppelin,
which Is credited with a speed of thirty
three or thirty-four miles an hour would
do little more than hold its own
AS to form, the cigar shape maintains
its favor. but the material of construc-
ton on which, it is argued, depends the
capacity of the balloon to remain in the
air, is varied. In Zeppelin's balloon the
envelope is entirely Of aluminium covered
with silk and rubber: in the military air
of the envelope is of metal covered with
silk and rubber. the ends and the upper
portions being of ordinary balloon ma
terial. while Parsevals balloon is en-
tirely composed of flexible material SINH
lar to that used in spherical balloons.
The voyages of the Parseval and mill
tary balloons. as well as of the French
airships. all of which are either semi
rigid or flexible. have been limited to
slightly over three hours owing to the
forward end of the envelope gradually
coiapsing through the escape of gas, thus
presenting a concave surface to the direc-
ton in which the balloon is steered and
preventing further progress
The only serious German experimenter
until now with flying machines heavier
than the air" Is Herr Karl Jatho, of Han
over. He has constructed a remarkable
aeroplane composed of six sails Ga hori-
zontal steering sail, a horizontal mainsail,
two vertical fixed sails and two vertical
steering sails) a wind propeller ana u
basket or platform carrying a twelve
horsepower motor. The equilibrium OF
the aeroplane is maintained by the hori-
zontal steering sail, which controls the
raising or lowering of the foreDart Of the
machine. Should the motor cease work.
Ing from accident or other cause. the
mainsail is large and strong enough to
act a parachute.