Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-05-06

which Is quite light and en- excellent non-con-
cuctor-a desirable quality to prevent waste OF
neat from the apparatus within.
| THE MOTIVE POWER.
| Inside this hollow shell are placed the works
that supply it with energy and motion. At the
head are located two tiny steam engines of the
double oscillating type. weighing only five
| pounds and capable of exerting one horse
power. They are veritable little giants in their
| way, and perhaps the highest one-horse-
power steam engines ever made for actual use.
\ Then in that portion corresponding to the mid
die of the fish are four little oblOng boilers,
| fabricated Of thinly hammered copper and
| weighing q trihe over seven pounds apiece
| They are supplied, instead of water, with
q volatile hypocarbon, which vapor-
| ICES at comparatively low tempera-
| ture. In the extreme end or tail of the fish is
| a little tank or receptacle with capacity Of
one quart, for the storage OF fuel-in this case
highly refined gasoline. Before passing along
the boilers the gasoline is voiatiiized By going
through heated coil. At the sides of the fish
are paddie-shaped twin-screw propellers or
wind fans OF pure aluminium, thinly rolled. To
these screws the little engines impart rotary
speed OF over 500 revolutions per minute.
THE AERoPLASEs
Through the center of the fish's body light.
tubular mast of aluminium projects upward and
downward. for the support of the aeroplanes,
corresponding to wings or sails. There two
OF these planes, one in front and the other be-
hind They are sector shaped, delicately made
and accurately balanced. Each consists of an
airy frame Of tubular aluminium covered with
Chlna SILK, presenting a smooth. fiat surface
to the air. The front plane is three and half
feet wide at the central angle and forty feet long
from tip to tip. Both aeroplanes are so ad-
1usted that the front edge is elevated above the
rear edge, the angle that is turned to the air
being capable Of regulation at will The aero
planes in nv Staya of al
mum wire connecting the tips with the extrem-
tiles OF the central mast and with the ends
OF the tubular backbone. By means Of this
rigging the whole exterior structure is trussed
up stiff and taut, after the manner of a sailing
ship, as indicated by the accompanyin drawing
engines. boilers, propellers, aeroplanes, attach
ments and all
RESULT OF THOUGHT, INGENUITY, SKILL, PA
THENCE AND MONEY.
To produce this working model required an
expenditure Of inventive thought, ingenuity.
money, mechanical skill. patience and persever-
ance that would have altogether deferred any or
binary experimenter. Each separate part. fea-
ture and appliance is the product of manifold
Investigations and repeated tests and repre-
sents the best results obtainable thus far in its
particular line. The various portions Of the
mechanism were fashioned and put together
with almost the same degree of precision and
nicely as characterizes q chronometer or
piece Of astronomical apparatus. The
whole as assembled and combined
embodies no less than four years unwearied
study on the part Of Prof. Langley and the
assistant scientists associated with him and has
cost in the neighborhood of $50. 900 cash. Part
Of this sum- considerable part-has come out
of Prof. Langley's private purse. A portion
also has been derived from special funds left to
the Smithsonian Institution by their donors for
nSai n ont uhi n
the remainder has been contributed by friends
interested in the development of TIE newly
enunciated principles of aero-mechanics.
TWO YEARS IN BUILDING.
The aerodrome was built and made to assume
its present shape in the chamber where it now
rests in the Smithsonian building. 1t was be-
gun nearly two years ago. Four high-class
specialists skilled in mechanics and metauurgy
were secured under strict injunctions and
pledges Of secrecy and set to work at COM
pensation Of so cents hour. pursuing their
task at odd intervals from time to time as its
exigencies permitted. The greatest possible
care WAS taken to keep away all out
siders, not only while the workmen
were actively engaged on the model. but even
at times when the work was temporarily sus-
pended. None of the regular attendants in the
building were supposed to suspect that the
making of such thing a flying machine was
going forward The materials were all con-
veyed to the construction chamber unseen by
spectators. Indeed, no one except the four
workmen and Prof. Langley and his assistants
were permitted to ascend to tine third floor at
all. and go guarded against premature publicity
were all the operations inside the secret cham
Der that the doors thereof we're kept securely
locked day and night.
In the large lecture room of the National
Museum, attached to the Smithsonian. Prof.
Langley repeatedly produced successful flight
with small prototype models Of the aerodrome.
Those little models would fy as long as the
power applied to them lasted. and would soar
as freely and lightly as birds from one end of the
hall to the other. The power was applied with
rubber bands wound tightly about cylindrical
axles. on the familiar principle of the boys
string top.
Elsewhere Prof. Langley demonstrated con-
vincingly that an @roplane could be made to
carry ESQ pounds to the horse power. One of
the great truths brought out was that it re-
qulres less and less power to maintain the hori-
zontal transport Of the plane the faster il goes
But the most important discovery made in
these experiments, Prof. Langley thinks is the
principle of aero-mechanics that If in such
aerial motion there be given a plane of liked
size and weight, inclined at such angles and
moved forward at such speeds that it shall
always be sustained in horizontal flight, then
the more the speed is increased the less will be
the power required to support and advance it,
so that there will be an increasing economy of
power with each higher speed up to some re-
mote limit not yet attained in experiment"
STEAM THE MOST SATISFACTORY.
Next to the aeroplanes the kind Of motor and
propeller used is an essential consideration.
Scientists have long conceded theoretically that
with a suitable motor given a successful fying
machine Is possible, and 1t is now agreed that
a steam engine OF sufficient liShtness is the most
satisfactory agent. As far back as 1890 Prof.
Langley succeeded after much trouble
N ha