The Helena independent. [volume] (Helena, Mont.) 1875-1943, 1891-02-08
AIR NAVIGATION.

tors that the idea OF voyaging through
the air has exercised a wonderful fas-
cination. There is something extreme
ly fiattering to human weakness in the
idea Of grasping one of the attributes Of
divinity and riding upon the storm. The
solution of the problem would crafty
mans natural desire for power, and
would mark an important forward step
in the long human struggle against
physical disabilities. Psychologists have
insisted that the pectoral muscles of the
human body are utterly incapable Of
the burden that flying through the air
would impose upon them. and the in
chimes of the past have succeeded adj
mirably in proving the correctness Of
the psychologists statement. The bal
loon is a success, as far as it goes, but
it does not 60 far enough. Its carrying
capacity is strictly limited by its cost,
and, in the absence Of steering power, it
is the mere creature of the winds. Our
knowledge of air currents has widened
the possibilities of its usefulness, bat
balloon travel is surrounded by too
many uncertainties anG dangers to
make it either popular or profitable.
The formation of the Mount Carmel
company quickened the public interest
in the matter. All difficulties, we were
assured, had been solved. A means Of
propulsion had been found, satisfactory
steering gear had been invented and a
new process had cheapened the cost Of
aluminium. Imaginative people began
to revel in the prospects OF a world Of
novel experiences, and even staid bust
ness men were inclined to pay respect to
a possible speed of two hundred miles
an hour. And when the news came of
the successful trial Of the model at Chi
cago, victory seemed assured.
But a recent article in the Mining and
Engineering journal throws a wet
blanket on the whole scheme. 1t does
not believe in the possibility of a lifting
power of $500 pounds, with a buoyancy
chamber ITO feet long and twenty-eight
feet in diameter. Such q chamber would
have a superficial area of not less than
$4,000 square feet and it's contents would
be about 10000 cubic feet. If hydrogen
gas is to be employed, the buoyancy
must be represented by a force equal to
the difference between the weight of
$4,000 cubic feet OF air and that of the
same bulk of hydrogen. Il. it is intend
ed to use a vacuum, the buoyancy due
to the weight of 10000 cubic feet of air
would ice some 1000 pounds. If we de-
duct from this the total weight of the
ship, which is set down at 1850 pounds,
that will give us a lifting power of $3.50
pounds, which is fairly near the pros
pectus figure. But it is in the weight
Of the air ship that the technical critic
finds his supreme difficulty. He is will
ing to put the weight OF the sheathing
alone at the full 1850 pounds, and he
SHOWS that that will only allow a weight
ofO.ll pounds per square foot. Alum
mum, one inch thick, weighs about 1871
pounds to the square foot, AMI an easy
calculation reduces the thickness of the
sheathing to about O.00S inches. No
engineer, he declares, would face the
problem Of building even a frame work
OF the requisite dimensions stiff enough
to prevent the collapse of the sheathing,
and to sustain the weight of itself, pas
sengers and machinery, that would
weigh only $500 pounds. And if that
be the minimum weight OF the neces-
sary framework, we must add to it the
weight of the sbeathing itself, of the
fifty passengers, and of a gas engine
weighing $50 pounds, and it is not very
hard to see that a lifting power of $500
pounds, if his figures are true, is %utterl,
inadequate, and that we must remain
content even yet with our ordinary
methods of transit.