Evening star. [volume] (Washington, D.C.) 1854-1972, 1893-11-04

the whole car being kept slightly elevated
at the forward end. Others could project
horizontally on each side from above the
windows. and from the top of the car. A
large one should cover the car like an avn
Ing, at such height that its after end will
be on horizontal plane with the highest
portion of the car when the bow is elevated
about degrees a IL feet in a car, with
6O-foot middle body, in order that all
the air passing between the car and avn
ing at the bow may press against the lat
ter before passing out. Other such awnings
may be placed above that, though each
should be shorter than the one below in
order that they may be properly stayed
fore and aft If the car has springs wheels
or other supports beneath. advantage should
be taken of them to stretch an aeroplane
below the car also.
The aeroplane surfaces should be some
what concave. curving both fore and aft
and athwartship, but especially the lat
ter. in order to resist the lateral spread of
the air and economize its supporting power,
as in thermometers. How much curvature
should be given must Of course be deter
mined experimentaily, from the natural
belly Of a taut sail to a flexible semi-cyIin-
der.
The support given by the aeroplane sur
face can be assisted by the propellers be-
Ing kept at about a right angle to the car,
and the whole canted about degrees or
somewhat less. And also. Of course. by any
additional cant given the propellers.
Propulsion and Power.
Twin screws-one placed forward and one
aft-the blades of the shape Of the Black
man fan wheels; the material. metal tubing,
covered with silk or linen Reversible
blades would probably be too risky where
everything depends upon them, and the ends
Of the blades should be bent to minimize
the great amount of slip.
BE 1t remembered in this connection, that
screw propellers and fan wheels can be seen
through, at whatever speed they are run.
For an engine. 1 propose. for experiment
a steam turbine. the shaft of the engine
being the shaft Of the propeller; the casing
of the engine the immediate support OF the
propeller. and pivoted on trunnions near its
center at the end of the car, so that IL NAV
be turned vertically when the wheels are
needed for lifting, explained under ascent
and descent. For this purpose the engine
should be as small in diameter as practi-
cable making II up in length) to give the
necessary power. The steam would of
course, be admitted through the trunnions
and have triple or quadruple expansion
both ways.
quires no base. The ''Turbo," made by G.
A. Parsons Co., New Castle-on-Tyne.
England. has worked perfectly, suspended
oy wire, and with super-heated steam
has recently proved very efficient
AS 10 the boiler. at first, the highest form
adapted to oil burning. But / wish to sug-
gest that here We probably haze a splendid
neld Tor the most economic boiler ever in
Vented-the solar boiler. Two elements
combine to that cnd-the altitude above
the denser portion of the atmosphere,
which absorbs very large percentage of
the suns heat. and the ability to rise above
the ordinary level of the dense clouds.
which make solar boilers impracticable In
most localities on the earth's surface. /
remember an experiment of scientific
party-under Prof. Langley. 1 think-upon
mountaintop in California to test the
amount of heat absorbed by the atmos-
phere. They placed some meat in a not.
laid a sheet of perfectly plain glass over
1t and set 1t in the sunshine, which actual
ly cooked It! If this could be done without
any concentration of the suns rays it
shows an immense heat available at a
practicable height when concentrated,
either by reflection, as in Ericcson's solar
boiler. or by refraction. This latter prin-
ciple Is the more economic of light and