made my own, and which I am determined to push to
a triumphant issue, he may be sure that he will receive the
acknowledgments of a grateful and earnest man, who has himself devoted
to it the aspirations and efforts of a long life, and who is still
willing to take all the risks of failure upon himself.

The undersigned would be pleased to have friends interested in this
subject, call upon him, when the matter will be more fully described.

ROBERT HARDLEY,

17 PERRY STREET, or

114 Sixth Ave., cor. 9th St.

[Illustration: THE AERIAL MACHINE.]

REMARKS ON THE ELLIPSOIDAL BALLOON,

PROPELLED BY THE

_Archimedean Screw_,

DESCRIBED AS THE NEW AERIAL MACHINE,

NOW EXHIBITING AT THE ROYAL ADELAIDE GALLERY, LOWTHER ARCADE, STRAND.

REMARKS, &c.

The object proposed in the construction of the Machine which is here
presented to the public view, is simply to illustrate and establish
the fact, that, by a proper disposition of parts and the application
of a sufficient power, it is possible to effectuate the propulsion or
guidance of a Balloon through the air, and thus to prepare the way for
the more perfect accomplishment of this most interesting and desirable
result.

In the contrivance of this design, one of the first effects aimed
at was to reduce the resistance experienced by the Balloon in its
progress, which is greater or less according to the magnitude and
shape of its opposing surface. To this intent is the peculiar
_form_ of the Balloon, which is an _Ellipsoid_ or _prolate
spheroid_, the axis of which is twice its minor diameter; in
other words, twice as long as it is broad. By this construction the
opposition to the progress of the Balloon in the direction of either
end is only one _half_ of what it would be, had it been a Balloon
of the ordinary spherical form and of the same diametrical magnitude.
For the exact determination of this proportion we are more
particularly indebted to the researches of Sir George Cayley, a
distinguished patron of the art, who, a few years back, instituted a
series of experiments with a view to ascertain the comparative amounts
of resistance developed by bodies of different forms in passing
through the air; the results of which he communicated to the world in
an essay first published in the Mechanic's Magazine, and afterwards in
a separate pamphlet. According to these experiments it appears, that
the opposition which an ellipsoid or oval (of the nature of the