rtions are made notwithstanding the
fact that only a few years ago, in the great exhibit
of aeroplanes in Paris, many unique forms of machines
were shown, all of them capable of flying,
as proven by numerous experiments, and among
them were a half dozen types whose length fore
and aft were much greater than transversely, and
it was particularly noted that they had most wonderful
stability.

DENSITY OF THE ATMOSPHERE.--Experts declare
that the density of the atmosphere varies throughout,
--that it has spots here and there which are,
apparently, like holes, so that one side or the
other of the machine will, unaccountably, tilt, and
sometimes the entire machine will suddenly drop
for many feet, while in flight.

ELASTICITY OF THE AIR.--Air is the most elastic
substance known. The particles constituting it
are constantly in motion. When heat or cold penetrate
the mass it does so, in a general way, so as
to permeate the entire body, but the conductivity
of the atmospheric gases is such that the heat
does not reach all parts at the same time.

AIR HOLES.--The result is that varying strata
of heat and cold seem to be superposed, and also
distributed along the route taken by a machine,
causing air currents which vary in direction and
intensity. When, therefore, a rapidly-moving
machine passes through an atmosphere so disturbed,
the surfaces of the planes strike a mass of
air moving, we may say, first toward the plane,
and the next instant the current is reversed, and
the machine drops, because its support is temporarily
gone, and the aviator experiences the sensation
of going into a "hole."

RESPONSIBILITY FOR ACCIDENTS.--These so-called
"holes" are responsible for many accidents. The
outstretched wings, many of them over forty feet
from tip to tip, offer opportunities for a tilt at one
end or the other, which has sent so many machines
to destruction.

The high center of gravity in all machines makes
the weight useless to counterbalance the rising
end or to hold up the depressed wing.

All aviators agree that these unequ