IMPROVEMENTS IN OBTAINING MOTIVE POWER FROM FLOW OF THE SEA, AND IN MACHINERY FOR APPLYING THE SAME
Year: 1869

page_text: LETTERS PATENT to Ferdinand Tommasi, of Rue du Colysée, No. 15,
à Paris, for the Invention of "IMPROVEMENTS IN OBTAINING MOTIVE
POWER FROM FLOW OF THE SEA, AND IN MACHINERY FOR APPLYING THE
SAME."
Sealed the 2nd October 1869, and dated the 5th April 1869.
PROVISIONAL SPECIFICATION left by the said Ferdinand Tommasi
at the Office of the Commissioners of Patents, with his Petition,
on the 5th April 1869.
I, FERDINAND TOMMASI, of Rue du Colysée, No. 15, à Paris, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN OBTAINING
MOTIVE POWER FROM FLOW OF THE SEA, AND IN MACHINERY FOR APPLYING THE
SAME," to be as follows:-
This Invention consists in utilizing force obtained from the ebb and

page_text: flow of the tide. In close proximity to the sea shore, or to the banks of
a tidal river, I construct a building divided into four principal compart-
ments, the two lower compartments being filled with water at high tide,
the third compartment acting as a reservoir for storing up air compressed
by the rising and sinking of the water, and the fourth and upper com-
partment serving as a workshop, and containing the air pump or com-
presser worked by the said compressed air and any other machinery that
may be required. The level of the floor of the lowest compartment is
rather below low-water mark, and the water is conducted thereto by
means of a suitable passage hereafter described, the level of the top of the
second compartment being near high-water mark. As the tide rises the
lower compartment gradually fills with water, the compressed air resulting
therefrom passing through a tube to the air pump or compresser, from
whence it is ejected into the third compartment containing compressed
air to be afterwards utilized in any convenient manner. The first com-
partment being full the water rises in the second and expells the air
therefrom in the same manner, the air being forced into the third com-
partment by the air pump or compresser, as before stated. As the tide
ebbs and the water descends a vacuum is formed in the two compart-
ments previously filled with water, and the air outside in endeavouring
to establish an equilibrium acts on the piston of the air pump or com-
presser, thence passing into the accumulating chamber through a suitable
valve, whereby it is compressed and ready for use when required. The
air thus compressed and accumulated in the third chamber may be
used to drive an engine for turning the shafting of a workshop or for
any other similar purpose where power is required, and I prefer to use
an engine having an oscillatory cylinder so that friction and other
injurious actions may be reduced as far as possible. In any convenient
position is placed a tube communicating with the pipe through which
the air passes from the chamber to the air pump, the said tube having
whistles or alarums placed thereon, by which means it is ascertained i
any of the parts of the apparatus are defective or not in proper working
order. On the sea side (by preference) of the building is a well, reaching
from above high-water mark to the floor level of the lowest compart
ment, and having hermetically closed doors leading into the said com
partments, so that they can be examined and repaired when necessary
Steps or ladders are used to descend to the lowest levels, and a raft i
employed in the bottom compartment, so that access can be obtained t

page_text: any part thereof. If the pressure of air in the accumulating chamber
becomes too great means are provided for allowing the air to escape
instead of passing through the air pump; and more than two chambers
for generating compressed air, and more than one for accumulating such
compressed air, may be used if desired. The passage or channel through
which the water passes to the lower compartment projects a suitable
distance into the sea, and is provided at its extremity with two inlets or
orifices, the one at right angles or nearly so to the other, and on each of
these orifices is fixed a pipe of canvass or other suitable material, kept
open by springs on the inside, and having gratings at their extremities,
by which means seaweed, shells, pebbles, and other injurious objects
are prevented from entering the pipe with the water. The outer ends or
extremities of these two pipes are always kept near the level of the
water by means of a float attached thereto, and as the two orifices of the
said passage or channel are at right angles one to the other one of them
is always full open at low tide and the other at high tide, the folds of the
canvass pipe closing to a certain extent the orifice that is not open, as
will be readily understood.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Ferdinand Tommasi in the Great Seal Patent
Office on the 5th October 1869.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FERDINAND
TOMMASI, of Rue du Colysée, No. 15, à Paris, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Fifth day of April, in the year of
our Lord One thousand eight hundred and sixty-nine, in the thirty-
second year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Ferdinand Tommasi Her special licence
that I, the said Ferdinand Tommasi, my executors, administrators, and
assigns, or such others as I, the said Ferdinand Tommasi, my executors,
administrators, and assigns, should at any time agree with, and no others,
from time to time and at all times thereafter during the term therein
expressed, should and lawfully might make, use, exercise, and vend,
within the United Kingdom of Great Britain and Ireland, the Channel

page_text: "
Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN OBTAINING
MOTIVE POWER FROM FLOW OF THE SEA, AND IN MACHINERY FOR APPLYING THE SAME,
upon the condition (amongst others) that I, the said Ferdinand Tommasi,
my executors or administrators, by an instrument in writing under my,
or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Invention, and in what manner tho
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent,
NOW KNOW YE, that I, the said Ferdinand Tommasi, do hereby
declare the nature of my said Invention, and in what manner the same
is to be performed, to be particularly described and ascertained in and
by the following statement and accompanying Sheet of Drawings (that
is to say):-
My Invention has for its object the utilization of power derived from
the waters of the sea alternately elevated and depressed by the ebb and
flow thereof. The apparatus that I employ for this purpose consists of
a combination of reservoirs, culverts, or conducting passages, and of
machinery, the action of which varies according as the tide is ebbing or
flowing.
1°. When the tide flows these apparatus directly compress air in a
reservoir, to be afterwards utilized as an active agent in driving
machinery.
2°. When the tide ebbs a vacuum is formed in a space above a reservoir
(the which space was filled with water during the flow of the tide), and
thus the exterior air exerts its pressure upon an intermediate machine to
re-compress the air in the first-mentioned feeding reservoir. The said
reservoir thus filled with compressed air forms an accumulator of motive
power that may be used at will to drive one or many engines. The
power of these engines will depend upon the amount of pressure of the
air and upon their dimensions, as well as upon the arrangement of the
intermediate reservoirs in which the level of the water is constantly
changing.
The air compressor and the engine that I prefer to use should be
specially constructed to avoid as far as possible passive resistances, such

page_text: as friction, adhesion, resistance of the air, and others. As the ebb and
flow of the tide take place twice a day a considerable amount of power
can be relied upon that will of itself cost nothing, and will require
few complications to manipulate it.
The Drawing annexed to this Specification clearly shews the general
arrangement of apparatus used to carry out my Invention. I erect in
some convenient locality near to the sea shore or to the banks of a tidal
river a strong building containing three reservoirs F, H, and K, arranged
one above another; the lower one F utilizes the flowing tide, the second,
H, is acted upon by the ebbing tide, and in the third or highest, K, the
air is alternately accumulated by the two first. The sea water enters
the lower reservoir F through the culvert C up to the level A, A,
(corresponding to low-water mark), and during the rising of the tide the
level of the water is gradually rising in the reservoir F, thus compressing
the air it contained and forcing it out by the tube G, through which it
is drawn by means of a pump or compressor N worked by the cylinder D",
and passes into the highest compressing reservoir K. The level of the
water still rising at length reaches the top of the reservoir H through
the tube R, and is either utilized in the same manner as the air from
the reservoir F, or left to escape without being used. When the water
has attained the level B, B, the two reservoirs H and F are full; the ebb
tide then commences, and with it the level descends in the reservoir H;
the air in this reservoir is thus rarified until the water has entirely
evacuated it, but meanwhile the exterior air, the pressure of which is
constantly tending to produce equilibrium, acts upon the face N¹ of the
piston of the cylinder D, and thereby causes the compressor N to act
and still further compress the air in the reservoir K through the valve L.
The two actions (the ebb and flow) produce therefore the same effect,
they both compress the air in reservoir K, and this air may be used when
desirable to work an engine O, into which it will enter by the pipe P.
The engine should be constructed under the most advantageous con-
ditions for the purpose for which it is designed. I prefer, therefore,
an oscillating cylinder, and a self-acting distribution of the air, so
as to avoid the friction inherent in most kinds of engines. The
admission culvert or passage C is formed at its mouth or entrance so
as to ensure a permanent feeding of the water and avoid obstructions
caused by seaweed, gravel, shells, and other injurious substances.

page_text: I prefer the following construction:-A float b, b, supports at all
times a little below the level of the water the ingress orifices of two
canvass pipes a, a, which are kept open by interior springs, and are
furnished with gratings, the rectangular position of the two orifices of
the culvert C ensuring there being always one pipe a open for feeding
the reserv oir F.
Warning whistles B", E", are placed in suitable positions to indicate
when the apparatus is not acting in a proper manner; D represents the
inclined surface of the shore or beach; E is a well or conduit to enable
an inspection of the working of the apparatus to be made; M, a pipe
for the free exit of the air from the reservoir F when required; Q, a
pulley on the shafting for transmitting motion from the engine o to the
different parts of a workshop; S, the interior of said workshop; T,
brickwork supports; U, horizontal beams dividing the reservoirs one
from another; V, the upper surface of the reservoir K forming the floor
of the workshop; X, outer walls of the building; Y, iron doors her-
metically sealed used for the examination of the reservoirs; Z, a ladder
to descend into the reservoir F; and A" a raft for enabling repairs to
be done to the said reservoir.
Having now described the nature and particulars of my said Inven-
tion, I claim, the means and apparatus for the utilization of the ebb and
flow of the sea as a motive power, as herein described and illustrated
in the accompanying Drawings, the chief characteristics of the Invention
being,-
First. The employment of two reservoirs utilizing respectively the
weight of the mass of water raised and depressed by the ebb and flow,
and compressing air in a third and higher reservoir to form the active
agent for driving one or many engines.
Second. The compressor set in motion by the alternate action of the
ebb and flow through the instrumentality of the first two reservoirs.
Third. The combination of culverts, hermetic doors, and inspecting
wells which enable accurate examinations of the various parts of the
apparatus to be made.
And, fourth. The combined arrangement of oscillating cylinders,

page_text: pumps, and other auxiliary apparatus to diminish the loss of force due
to friction.
In witness whereof, I, the said Ferdinand Tommasi, have here-
unto set my hand and seal, this Twenty-ninth day of September,
in the year of our Lord One thousand eight hundred and sixty-
nine
Witness,
CH. ARMENGAUD,
Civil Engineer,
FERDINAND TOMMASI. (L.S.)
Boulevard de Strasbourg, 23,
Paris.