IMPROVEMENTS IN OBTAINING MOTIVE POWER, AND IN THE APPARATUS EMPLOYED THEREFOR
Year: 1866

page_text: PROVISIONAL SPECIFICATION left by Aristide Gerard at the Office of
the Commissioners of Patents, with his Petition, on the 23rd August
1866.
I, ARISTIDE GERARD, of No. 15, Avenue Matignon, Paris, in the Empire of
France, Engineer, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN OBTAINING MOTIVE POWER, AND IN THE APPARATUS EMPLOYED
THEREFOR," to be as follows, that is to say:-
My Invention consists of means and apparatus for producing a continuous
or intermittent motive power, as herein-after described, and is founded on the
following principles :-
Any body being plunged in a liquid is submitted to two opposite forces;
first, its own weight, which tends to lower it; secondly, the pressure of the
liquid which tends to raise it with a force equal to the weight of the liquid
displaced by the body. The difference between these two forces constitutes
the principle of what I call Gerard's new motive-power engine.
In the annexed Drawings Figure 1, Sheet 1, is a front elevation, and
Figure 2, Sheet 2, a side elevation of Gerard's motive-power engine.
A shews two cylinders full of liquid united together by the uprights B;
these uprights are perforated in the centre for the passage of the pivots D of
the shaft C, forming one piece with the uprights B. The two pivots D rest
in bearings fixed on the standards E. In the interior of each of the cylinders
is a float F supporting a rod G. The rod of each float sets in motion the
crank axle.H by means of the connecting rods I; the extremity of the axis C
carries a fixed ratchet wheel J turning with the axis; by means of the click K
this ratchet wheel communicates its movement to the loose pulley L. Now it
will be easily understood that the pulley L must always turn in the same

page_text: direction, and that its movement must reach its maximum by the new
impulse which is communicated to it at each ascension of the floats. The
apparatus being left to act the floats will rise by virtue of their lightness.
The ascensional movement of the floats being terminated, the apparatus must
be turned over, so that the floats may be ready to begin another journey.
This rupture of equilibrium can be effected in different ways, I will describe
two distinct modes.
In Figures 1 and 2, Sheets 1 and 2, N represents two cupolas or vessels;
one of these cupolas is above the other below the apparatus; each of them is
fixed to it by means of the uprights M. O shews a tub or vat above the
apparatus provided with a cock P; the speed of the flow from this cock is
calculated so that it shall fill the cupola Q while the apparatus makes half a
revolution. This cupola Q is suspended freely on its axis, so that the meeting
rod R throws it over and empties its contents into the cupola N; this latter
also free on its axis is provided at its lower extremity with a rod S, which
meeting at the lower part of its play with the cross bar T is turned over, and
discharges the water which it contained, while the cupola at the upper part is
by this time filled. .
To obtain a greater regularity of the flow where water from a hydrant
should not be obtainable, the feed tub or vat could be provided with one of
Prony's floats, and the water thrown off would by means of a pipe be brought
back into the reservoir below the tub or vat. It will be easy to find the
minimum of water necessary for breaking the equilibrium by elongating
progressively the uprights of the cupolas. In certain cases this repeated
discharge of water can be again utilized either as motive power or as inde-
pendent of or added to that produced by the principal motive power.
Figure 3, Sheet 2, of the Drawings shews what I call an auto-motive
power engine, that is to say, an engine self-generating and reproducing its
power.
a, a, are two cylinders each enclosing two floats h, h, h, h¹, connected
by means of rods c, c³, and united to the connecting rods d, d', by two
rods e, e¹, motion is thus communicated to the crank shaft f, round which the
whole mechanism turns.
In the description of the apparatus which precedes the present, it has been
shewn that the most important point to be obtained was the rupture of
equilibrium at the same time that the two floats had finished their play. In
Figure 3 of the Drawings this rupture is shewn as taking place naturally by
means of the pipes 9, 9', g¹¹, 9¹¹¹, with which each of the floats is furnished.
The upper floats h, h³, for instance, rise pushing up the pipes g. 9', which are

page_text: ay, that is to say, av
brium has become necessary.
The proc
GENERAL REMARKS.
In the construction of my automatical motive-power engine it is important
that the pipes brought to the floats should be susceptible of sliding freely in
their jackets without water getting in. This may be effected by means of
pipes fitting one into the other, and by only letting out a rod, or by isolating
the eduction pipe by means of a waterproof and very flexible envelope forming
a cylinder, the two ends would be fixed, one to the bottom of the cylinder the
other to the bottom of the float; a series of small light rings guided in the
interior by small rods for preventing their coming close to the pipe serve to
keep this envelope always open.
The form of the floats is also of great importance. The cylindrical conical
form is suitable for the engines at full speed, but it has the disadvantage of
increasing the distance between the axis and the extremity of the cylinder, and
consequently of requiring a longer time for the fall by which the floats are
brought down. I consider that the spherical form unites in exact proportions
the conditions of power and speed, and has the advantage of better resisting
pressure, and this permits of making the floats lighter.
I have adopted in my experiments the form of a cylinder, the two ex-
tremities of which are slightly convex; an orifice perforated in the centre
diminishes the ascensional resistance.
All liquids produce results in proportion to their respective densities,
consequently twice more power will be obtained for the same speed with
bromium than with water; thirteen times more with mercury, or vice versà,
thirteen and a half more speed for the same power.
It is important to employ in the construction of the cylinders and floats
materials which cannot be affected by the liquids which are to be employed.