IMPROVEMENTS IN THE PRO- PULSION OF SHIPS AND VESSELS."
Year: 1874

page_text: LETTERS PATENT to George Tomlinson Bousfield, of Sutton, in the
County of Surrey, for the Invention of "IMPROVEMENTS IN THE PRO-
PULSION OF SHIPS AND VESSELS."-A communication from abroad by
Eugène Louis Jules Ebaudy de Fresne, of 10, Boulêvart de la
the Danublic of Trance

page_text: administrators, and assigns, Her Royal Letters Patent for the same,
and have made solemn Declaration that it is a communication to me
from abroad by Eugène Louis Jules Ebaudy de Fresne, of 10, Boulevart
de la Madeleine, Paris, in the Republic of France.
NOW KNOW YE, that I, the said George Tomlinson Bousfield, do
hereby declare the nature of the said Invention to be as follows:-
This Invention has for its object improvements in the propulsion of
ships and vessels.
The Invention may in general terms be said to consist in replacing all
mechanical agents, such as paddle wheels, screws, &c., however actuated,
by the action of a column of air incessantly discharged against the liquid
under the water line by means of one or several force pumps worked by
steam power or otherwise. The water being displaced by the violent
flow of the air against the liquid necessarily produces the propulsion of
the floating body (ship or vessel) in the direction opposite to that of the
flow in consequence of the displacement of the volume of water by the
air and the force exercised by the air in its flow.
In practically carrying out this new mode of propulsion three
principal methods may be used, although of course modifications of
detail will be necessary on account of the various formations of different
ships and vessels, and from the fact that the conditions of navigation
will not be the same in calm as in rough water or with slow speeds
(when economy is desired) as with fast speeds when other objects are in.
view..
In the first method the water is allowed to penetrate into the ship by
means of one or more longitudinal passages freely open at the end
exterior to the ship and closed at their other extremity. The air is
pumped in by the force pump at the inner closed extremity and expels
and replaces the water. The propulsion of the ship or vessel necessarily
results since the passage will be emptied of the water which is expelled
and filled with the air which has replaced it. This air is allowed to
escape by one or several upper passages, and is permitted to return to its
starting point; the water is allowed to re-enter by various openings so
arranged as to give it admission as quickly as possible so as to permit of
its being again expelled by the air through the extremity which has
been left open for its exit. A constant propulsion is thus produced, the
water being alternately allowed to enter and then-being again expelled,

page_text: These interior passages of the ship should by means of flaps.and.valves
be mechanically closed at one extremity when the air is driving out the.
water and then mechanically opened to allow the air to escape and the
water to re-enter.
•
In this first method of carrying out the Invention there is a true
reciprocatory movement, which can be transformed into a continuous
movement by the use of two of the apparatus at the least emptying
themselves and refilling with air and water alternately with one another,
the one allowing the water to re-enter whilst the other is expelling it.
The action however of the compressed air on the enclosed water gives
rise to mechanical complications, which although permissable in calm
water become a grave objection to the system for rough water.
.
The second mode of application, the simplest mechanically, consists
in constantly forcing the air against the exterior water through a per-
manent opening at the extremity of the ship, and as low down as
possible. The air is constantly forced through this opening with
violence against the water by the alternate action of at least two pumps
forcing the air in turn into a common reservoir, so that the emission of
the column of air is continuous. In this case the passages by which
the air goes out need not be of a greater length than that necessary
to give the proper direction to the air as it is forced against the water.
In the third mode of application the air is retained in the passages
in which it flows by valves, which will only open when whe pressure of
the air produced by the force pumps exceeds a certain degree.
To obtain the continuous movement the canals by which the air passes
are momentarily closed until the pressure is at least doubled and the
almost explosive escape of the air results, and this going on alternately
in the apparatus gives a constant propulsion, although it is obtained by
impulses. In these machines the compression of the air can be carried
to several atmospheres.
To manœuvre and back the ships and boats apparatus similar to that
used at the stern is placed at the bows. It suffices that they should be
directed in the opposite sense the one to the other, the rudder being used
in the ordinary manner. It will even be easy by means of a double
identical apparatus acting at the two extremities of the ship and with a
rudder at each end, the one working and the other fixed according as
the one or other extremity of the ship is in front to avoid going about

page_text: whenever the circumstances of navigation or working render this'
manoeuvre superfluous or dangerous.
The canals or passages in the body of the ship by which the water
and air enter and escape ought to be as much rounded as possible
in order to diminish the loss of power by friction, but they may have 5
any shape so as to accommodate themselves in the most convenient
manner to the construction of ship in which they are used.
In witness whereof, I, the said George Tomlinson Bousfield, have
hereunto set my hand and seal, this Seventh day of July,
in the year of our Lord One thousand eight hundred and seventy- 1
four.