IMPROVEMENTS IN PRODUCING OR OBTAINING MOTIVE POWER
Year: 1859

page_text: PROVISIONAL SPECIFICATION left by Bartolommeo Predavalle at the
Office of the Commissioners of Patents, with his Petition, on the 15th
December 1859.
I, BARTOLOMMEO PREDAVALLE, of Bloomsbury Street, Bloomsbury Square,
in the County of Middlesex, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN PRODUCING OR OBTAINING MOTIVE
POWER," to be as follows:-
My Invention relates to the combination of certain mechanical means in
connection with a peculiar property of fluids and a pneumatic action for the
purpose of producing or obtaining motive power. According to this Invention,.
motive power is produced by the vertical pressure of a column of fluid alter--
nately changing its action on the beam of a balance. For this purpose a thin
column of fluid is caused to exert vertical pressure on a body of fluid contained.
in a vessel of larger base than the diameter of the column. I employ a vessel
consisting of separate parts kept in contact, and fix vertically thereto in the
upper part a pipe or tube, which communicates with the interior of the vessel
and is filled with fluid, so as to obtain a pressure in the vessel equal to the
weight of a column having the diameter of the vessel's interior and the height.
of the pipe. The bottom of the vessel is rigid, and detached from the other
parts of the vessel, to which it is, however, made to adhere, forming
an air and water-tight joint. The vessel is of cylindrical or other convenient
form, and is connected to one end of a beam at two points of its circumference,
forming pivots, so as to move freely in a vertical or horizontal direction, like
the compass, on what is called a Cardan movement, in order to remain always

page_text: horizontal when the beam is rising or descending. The cover of the vessel
forms the bottom of a vessel or chamber from which the air is exhausted, so
as to form a vacuum total or partial inside. This vacuum chamber has the
top and bottom and sides rigid, or the sides may be flexible like bellows, in
which case some rigid supports must be placed between the top and bottom
plates to prevent collapse. In the centre of the top and bottom plates of this
chamber are two holes, through which a thin flexible pipe passes, and com-
municates with the interior of the vessel containing the fluid, or the pipe
without passing through the vacuum chamber may be connected by one or
two branches with the interior of the vessel. This pipe, which may be in part
flexible and in part rigid, is connected to the frame, and continued to the
height desired, and is made to rise and descend freely to the extent of the
stroke with the beam, at the extremity of the circumference of the top plate of
the vacuum chamber; and between the two pivots with which the vessel is
connected to the beam is attached a chain, which passing under the vessel and
rising vertically on the opposite side, is fixed to the upper frame of the
machine, so that when the vessel has completed the down stroke it turns
round the two pivots, and is reversed upside down. This arrangement
produces this effect, that when the vessel is in its normal position the pressure
of the fluid on the bottom of the vessel, and the pressure of the atmosphere on
the top plate of the vacuum chamber, act downwards and cause the beam to
descend, and when the vessel is turned over the action is inverted. A similar
contrivance is arranged to cause the reversal of the vessel when it has reached
the end of the up stroke; on the other end of the beam another apparatus
precisely similar to that described is adapted. The machine is so arranged
that when the apparatus on one side descends, that on the other side rises.
The action is then reversed, and thus a reciprocating motion up and down is
obtained by the pressure of the column of fluid acting on the bottom only.
Motion thus obtained may be applied directly or transmitted vertically,
horizontally, or inclined, or converted into rotary or other motion by suitable
appliances. The power so obtained may also be caused to compress liquids,
steam, or other aeriform or gaseous fluids in a separate vessel, in order to
drive pistons or communicate motion to an archimedian screw, wheels, or
other contrivances, and may be adopted in substitution of steam, water power,
or other agents for working any arrangement of known engines.
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