Savannah morning news. [volume] (Savannah) 1868-1887, 1882-07-13
SHALL NE FLYg
Important end Perhaps Practical
Calculations Made by an English
Engineer n she Possibility OF Ae-
rial Navigation.

Aerial navigation, along with per
petual motion, has been driven from the
workshop to the mad house. The
problem has been given up by most
practical men and considered impos-
sible of solution by the world in general.
Bnt the subject has recently again been
discussed in. England with such plain
mechanical calculations and by such
practical engineers that it is likely
to attract fresh attention and pos
sibly to cause other and more
intelligent experiments. There are sew
eral recent mechanical inventions and
improvements that, if properly applied
10 aerial navigation, may overcome the
hitherto lnsuperable difficulties Van
Nostrand's Engineering Magazine for
July contains a paper read before the
Institution of Civil Engineers by VIM.
Pole, F. r. S., in which a practical ap
plicatiOn is made of several important
recent mechanical improvements to the
problem. 1t may now receive intelli-
gent instead of fanatical attention.
The first important step towards aerial
navigation at will was made by the ap-
plication of the screw propeller to bal
loon. In 1850 MIR. Henry Giffard con-
structed an elongated balloon, to which
| he attached a Tudder and a keel, and it
assembled with an engine of thTee.hOrse
power, which gave the screw power to
prOpel the balloon at an independent We
| locity of from four and half to six and
three quarter miles per hour. The bal
loon was steered at will. and the result
was theoretically all that could be de-
sired. Improved the important theory that
propeller and a rudder attached to
an elongated balloon would enable it to
be propelled and directed at will. The
two great problems - propulsion and
steering-were thus solved. But there
were still great practical difficulties. Ia
1850 the envelope of the balloon could
not be made impenetrable, and there was
no very cheap method known of prepar-
ing pure hydrogen. Besides these and
other less important difficulties of con-
struction, the balloon would sup
port no greater weight than one
person besides the engine and
the propelling apparatus. This OBJ.
| lection and the lack of speed, of
course, made it valueless. During the
siege of Paris. in 1870, the naval archi-
tect of the French Government, NJ
Dupuy de LONE, made another expert
ment similar to Giffards with similar
results. Instead of an engine his power
was the hand power of eight men. The
practical difficulties that he could not
overcome were of the same kind as Gift
faTd's-lack of speed, the inability to
carry anY cargo, and many smaller diff.
culties of construction.
Since these experiments the weight per
horse power of engines has been greatly
reduced and Improvements have been
made in the manufacture Of hydrogen,
in the structure of envelopes of balloons
and in many other mechanical devices
for lessening the weight of machinery
and increasing its power. At any rate,
no satisfactory tests have been made
of these recent inventions in such
an application. The experiments of
Giffard and De LONE lacked
only speed and carrying power
to prove the practical value of balloons
propelled by screw propellers worked by
steam. By simple and ineligible cal
culatiOn Mr.. Pole has reached the fol
lowing results; Maximum diameter of
the elongated balloon, 30 feet length ITO;
total ascending force, 1870 pounds;
weight of structure, 1870 pounds; availa
Bile ascending force. 600 pounds; horse
power of motor, 3; weight disposable
for cargo, after allowing for fuel and
water land rinsing water by condens-
ing steam-an important improve
ment made since Giffards experiment.,
% cwt. maximum speed through the
air, independent Of wind, 10 miles per
hour A balloon 100 feet in diameter,
with $40 horse power motor, would have
avsiable weight for cargo of 49, tons,
and could make speed of 80 miles per
hour, Independent of the wind.
These calculations are astonishing
more because they are simple and rest
on basis on experiments than because
the results that seem attainable are so
astounding. Are we really to have
serial navigation at last, or are more
engineers going TO the mad-house2