Evening star. [volume] (Washington, D.C.) 1854-1972, 1890-10-18


pose OF contributing forward motion.
The great difficulty in aerial~navigatlon has
always been held to exist in the tenuous nature
of the atmosphere. A ship Is easily padded
along, because the water is sufficiently dense
to afford resistance 10 its wheels or propeller
But air affords u comparatively slight resist
ance, and therefore il has been asserted that
propulsion through this latter medium was i'm
possible with the aid of such appliances as are
at present known to mechanical art
Curlously enough this belief which has been
20 generally received hitherto, is now regarded
as untenable. Science steps forward today and
says that il is only necessary to make the prop
erly designed propeller revolve last enough in
order to force the air ship along at a rate of
speed indefinitely fast. And the same prin-
cIple applies to the fans employed for the pur-
pose of raising or lowering the floating vehicle.
ALUMINIUM THE MATERIAL.
The mechanical art Of flying has accordingly
taken an entirely different shape within short
time. The key to its expectations at present is
found in the magic word aluminium" One
naturally considers a metal necessarily
heavy thing; but aluminium is as light as chalk.
A spoon OF lt-and much Of such table ware is
now manufactured from this material-feels
like feather compared with its likeness IN
silver. Furthermore, the tensile strength of
aluminium is SO great that huge tanks for con-
tanning liquid fuel can be made of it. The
flying machine Of the immediate future, which
may fairly be regarded as o thing almost on
the point OF successful accomplishment. will be
composed largely of aluminium, alleged with o
small percentage Of some other metal for the
sake OF hardening. Five per cent OF silver il
often used for the purpose.
FUEL AND MOTIVE POWER.
As at present contemplated, the air coach
will be run by steam obtained from liquid fuel
or the Burning Of the gas that is compressed
and loaded before starting into cylindrical res
ervoirs OF thin drawn steel tubing. A gas, con-
sisting as il does of molecules separated from
zach other and flying every which way. Is read
lily compressed, so that q single reservoir may
be made to hold 100 times its cubical contents
Of such q material Thus the air ship can take
on board a great quantity of fuel in exceedingly
small shape. BY transforming this fuel
through combustion into steam the engine will
be operated, the fans will be made to revolve at
a tremendous rate of speed and the air ship,
rising like a bird from the ground, will be d.
rected by the steersman to any point Of the
Compass that may be desired.
OF some such nature will be the air ship Of
the almost immediate future, whether or not
there proves to be any reality or practicabiity
In the scheme of the Illinois company which
has been advertised about to run Pullman
cars by the atmospheric route from Chicago
to New York and return in six hours without
any stops at way stations.
SAFETY, SPEED AND COMFORT.
In discussing this problem it is worth re-
membering that the solution Of the question of
aerial navigation does not imply getting up to
any great height above the surface of the
earth An elevation of 100 or 200 feet would
be quite sufficient for purposes of ordinary
travel. though necessarily the engineer should
be able to increase this somewhat at will
Three points must be kept in view regarding
passenger traffic Of this sort conducted for COM
mercial purposes namely, safety. speed and
comfort. For the sake OF safety the mechanism
must be constructed III a substantial way the
cars must be equipped with life boats lest
drop into deep water cause loss of life, and a
complement OF parachutes might be provided
for the use Of people who wished to drop off at
odd points For there is reason to believe that
IL will be long before the difficulty OF landing
an air ship with ease and without danger
10 overcome Speed, as has been already
said will depend upon the rapidity
with which the propellers are mado to revolve
This will be modified, of course by the
strength OF any current Of wind opposing the
progress of the aerial vehicle. If the latter is
going at the rate OF 100 miles an hour and il
opposed by a breeze with power of 40 miles
an hour, it goes without saying that the ship
will progress only at the rate Of 90 miles an
hour. Another thing to be considered is that
the resistance offered by air that is not in
motion varies as the square of the velocity of
the vehicle passing through it. In other words
II the car requires a certain force 10 propel it
at the rate OF Is miles an hour, it will require
four times that force to make it 60 80 miles an
vi tHc same IOrc0 10 give
II speed OF 60 miles an hour. All this must
be taken into consideration by makers Of flying
machinea
ONE GREAT DIFFICULTY
In the navigation Of the air has always been
found to exist in the weight Of the engines
necessary to operate the fans for lifting or pro-
polling. Happily, modern invention has gone
far to do away with this trouble. The four
horse power Copeland marine engine now on
the market weighs only "a pounds and occu-
pies q floor space of but 10 inches square, its
height being 81 inches. Boiler inc uded, il
weighs much less than the average man
There Is no reason whatever. IL 10 claimed WHY
many parts OF such engines should not DO made
OF aluminium instead Of steel
cosr OF ALUMINuM.
Il must be said that great deal Of what has
recently been written regarding aluminium is
untrue. Among other reports on the subject
10 has been asserted that the metal can now be
produced for the astonishingly low price of if
teen cents pound The fact is that by the
process newly discovered il can be turned out
81 the Wholesale rate of 81 pound by the ton
The method employed is very simple o cur
rent from q dynamo being passed through q
mass Of cryolite, which 10 a very cheap mineral
containing aluminium, nuorine and potassium.
By Ihls current the cryolite Is melted, and the
aluminium, sinking TO the bottom of the car
bon box IN which the cryolite has been put is
dipped out with q spoon. All the cryolite
uulzeo Tor TINS purpose IL brought from Greer
land, where alone il IL discovered In sufficient
Quantities to make the mining Of il worth
while. Even in that land Of cold the
supply OF 1t Is not inexhsustible; but, il il
should give out, corundum, an oxide Of alum
inom, VIII do as well, aud il is found in endless
Quantities not far south Of Washington. Nearly
al rocks are ore beds Of aluminium; every clay
bank 10 mine Of it; . brick house contains
tons of it, IN fact, it forms one-tfth part of the
carth's crust IL is white as silver, untarnish-
al In rAl.N Iaxhe h.. Il. Il.
and some Of its alloys are almost as hard Al
steel II 1t should prove the flying metal of
the future IL will indeed have earned a digni-
FED position among the elements that compose
the world
COST OF An AIR SHIP.
Althouoh aluminunu coata ~ o00 :. A., "A in