AN IMPROVED HYDRO-THERMIC MOTIVE-POWER ENGINE
Year: 1874

page_text: LETTERS PATENT to Ferdinando Tommasi, of Paris, in the Department
of the Seine, and Republic of France, Gentleman, for the Invention
"
PROVISIONAL SPECIFICATION left by the said Ferdinando Tommasi
at the Office of the Commissioners of Patents, with his Petition,
on the 24th August 1874.
I, FERDINANDO TOMMASI, of Paris, in the Department of the Seine,
and Republic of France, Gentleman, do hereby declare the nature of
the said Invention for "AN IMPROVED HYDRO-THERMIC MOTIVE-POWER ENGINE,"
follows: :-
to be as
This machine is composed of two or more cast-iron cylinders lined
with wood, millboard, or other isolating material, and filled with oil,
glycerine, or other suitable liquid. Into this liquid plunge a certain
quantity of small copper or other metal tubes bent into the form of a
lengthened U.

page_text: The two ends of each tube each terminate in one of two basins con-
tained in a bronze piece, upon which all the tubes are fixed and soldered.
A bronze washer fits on the two basins in such a manner as to completely
separate them.. Two tubes are fixed upon this washer, cach tube corrc-
sponding with a basin. The result of this arrangement is that by causing
either steam or hot water to penetrate into one of the last-mentioned
tubes this hot water or this steam immediately spreads in one of the
basins, enters one of the ends of the small tubes, and immediately issues
by the other tube of the washer after passing out of the other end of the
small tubes and by the other basin.
The oil or the glycerine heated by contact with the small tubes, in
which circulate the hot water or steam, immediately expands and drivos
the piston out of its cylinder. When the piston has completed its stroke.
the slide box set in motion by a cam suddenly stops the circulation of
the steam or hot water and immediately replaces it by a circulation of
cold water. The oil or glycerine is then condensed and the piston is
compelled to return to its original position, which gives it the come-and-
go motion of ordinary condensing steam engines.
The piston being similar to those of ordinary hydraulic presses can only
work with simple action, and it is therefore necessary to have. at least
two pistons set in a straight line on the horizontal shaft and a fly to over-
come the dead point. If it is desired to dispense with a fly wheel, as for
tramways and steamboats, there should be at least four pistons, cach
couple being set in relation to the other at a right angle on the hori-
zontal shaft. A space reserved in each cylinder and filled with com-
pressed air gives to the liquid the elasticity in which it is wanting.
i
The movement of the machine may be accelerated by means of toothed
wheels and pinions, or driving bands and pulleys.
If the machine is worked with hot water, and this I find preferable,
the boiler in which the water is constantly heated will have a special
arrangement permitting the machine in working to constantly return
into the boiler the hot water which has circulated through the small
tubes, thus giving a great saving of heat. This arrangement consists in
adding to the boiler as many feed recipients as there are cylinders in the
machine. The movement of each piston places all the recipients suc-
cessively in communication with the boiler, and causes the water which
they contain to run into. the boiler. These recipients are constantly.

page_text: filled by the hot water escaping from the cylinders after having caused
the expansion of the liquid with which they are filled.
It is necessary to have as many safety valves as there are cylinders.
Each safety valve presses upon a solid washer of " clinquant," which
prevents any oozing of the liquid, but which is torn by the liquid if the
desired pressure is exceeded.
For changing the come-and-go motion of the pistons into a circular
movement and the other mechanical details the same picces may be used.
as in steam engines.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Ferdinando Tommasi in the Great Seal Patent
Office on the 22nd February 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FERDINANDO
TOMMASI, of Paris, in the Department of the Seine, and Republic of
France, Gentleman, send greeting.
.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patcut, bearing date the Twenty-fourth day of August,.
in the year of our Lord One thousand cight hundred and seventy-
four, in the thirty-eighth year of Her reign, did, for Herself, Her
heirs and successors, give and grant unto me, the said Ferdinando
Tommasi, Her special licence that I, the said Ferdinando Tommasi,
my executors, administrators, and assigns, or such others as I, the said
Ferdinando 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 King-
dom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "AN IMPROVED HYDRO-THERMIC MOTIVE-FOWER ENGINE,"
upon the condition (amongst others) that I, the said Ferdinando
Tommasi, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should par-
ticularly describo and ascertain the nature of the said Invention, and

page_text: in what manner the 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 Ferdinando 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, reference being had to the accompanying Sheet
of Drawing, and to the figures and letters of reference placed thereon,
Figure 1 being an elevation of a motive-power engine embodying my
Invention Figure 2, left side view of same; Figure 3, plan; Figure 4,
vertical section at C, D, Fig. 3; Figure 5, vertical section at B, K,
(Fig. 3); Figure 6, horizontal section at H, I, (Fig. 1); Figure 7,
vertical section at F, G, (Figure 6); and Figure 8, vertical section at
M, N, (Fig. 3.)
This machine is composed of two or more cylinders of cast iron or other
metal lined with wood, millboard, or any other suitable isolating material
and filled with liquid (oil, glycerine, or other suitable liquid,) into which
plunge a certain quantity of small copper or other metal tubes, all bent
into the form of a very much lengthened U.
The two ends of each tube cach terminate in one of two basins,
formed by two bronze washers, the one superposed to the other so as to
completely separate these two basins. Two tubes are fixed upon the
upper washer so that each tube corresponds with a basin. The whole is
firmly fixed by the aid of strong bolts upon the orifice of the cylinder so
as to render any escape absolutely impossible, see a, Figs. 1 and 3. The
result of this arrangement is that by causing steam, hot water, or any
other hot liquid to penetrate into one of these tubes this steam, water,
or other liquid immediately spreads in one of the basins, enters one of
the ends of the small tubes and immediately issues by the other tube of
the washer after passing out of the other end of the small tubes and by
the other basin.
The oil or glycerine heated by contact with the small tubes in which
circulate the heat expands and drives out the piston 6 (Fig. 5), which
plunges into the same liquid as as for the pistons of ordinary hydraulic
presses. When the piston has completed its stroke the slide box set in
motion by a cam fixed on the same shaft as the piston turned by
means of a connecting rod and lever arm, suddenly stops the circulation

page_text: of the heat in the small tubes and immediately replaces it by a circu-
lation of cold water or other cold. The oil or glycerine is then con-
densed, and the piston is compelled to return into the cylinder, but at
the moment that its return movement is completed by the action of the
same cam, the slide box suddenly stops the circulation of cold water
and immediately replaces it by a hot circulation which again drives out
the piston. The result is a come-and-go motion, as in ordinary condensing
steam engines.
The piston being a plunger like those of ordinary hydraulic presses can
only work with simple action; it is therefore necessary to have at least
two pistons set in a straight line on the same shaft plunging into two
separate liquids and a fly to overcome the dead point. If it is desired to
dispense with the fly wheel, as for tramways and navigation, there
should be at least four cylinders with pistons arranged in couples, each,
couple being set in a straight line, and the two couples at a right angle
on the rotary shaft. Three cylinders might also be used, their pistons
set on the shaft, so that there will always be one piston in full stroke
when the others are at the dead point. A space reserved in cach cylinder
and filled with compressed air gives to the movement of the piston the
elacticity which the rigidity of the liquid would absolutely deny it.
This arrangement also gives another advantage, and that is that the
cranks of the shaft never stop at the dead point. To avoid any con-
fusion this space is not shown in the Drawing. If the speed of the
machine is less than desired the power of this machine is used to
compress air to be afterwards employed as required like steam at the
desired speed, or by the aid of racks, pinions, toothed or friction wheels,
or driving bands and pulleys, the powerful but relatively slow move-
ment of the machine may be transformed into a movement more rapid
and proportionately less powerful.
If the heat is produced by hot water the pressure of the steam upon
the surface of the water contained in the boiler c forces this water out
by the tube d at a speed in accordance with the pressure of the steam.
If the hot liquid is not water and produces no steam a certain quantity
of compressed air is introduced into the boiler, the compression of
which air will be constant, because as we shall see the volume of liquid
will always be constant. This result is obtained by means of the
suction and force pumps e, which constantly inject into the boiler the
same quantity of liquid as leaves it. These pumps which, if required,

page_text: might act on the hot liquid by the intermediary of a certain quantity of
air alternately rarefied and compressed draw the hot water into the
receivers where runs off the water which has circulated in the above-
mentioned cylinders.
If deemed desirable these pumps might also be replaced by the
following arrangement :-Above the boiler is placed as many receivers
as there are cylinders in the machine; cach receiver is constantly fed
with the warm water which issues from one of the cylinders after
liaving circulated in the small tubes. One or several special cams,
acting upon special slide boxes, place each receiver successively in
exclusive communication with the steam and the water of the boiler.
The result is that the pressure of the steam drives back successively into
the boiler the hot water contained in one of the receivers, while the
others take the hot water from their respective cylinders. The distri-
tributing slide boxes are so arranged that they produce not only the
alternate circulation of cold and heat in the small tubes, but also the
absolutely separate issue of the hot water and the cold water, which
permits the utilization of the one as well as the other.
It is necessary that each cylinder be provided with its safety valve.
This valve rests upon a solid washer of "clinquant" (very thin copper)
which prevents any oozing of the liquid, but which is torn thereby if its.
pressure exceeds the degree fixed beforchand. To avoid confusion this
valve is not shewn in the Drawings.
The accompanying Drawings represent the application of the hydro-
thermic principle to a fixed engine, but it is evident that it may also
be applied very advantageously to tramway traction and to navigation
particularly, because of the absolute impossibility of explosion and of
the exceedingly small bulk of the boiler compared with the size of a
steam boiler of equal power. To render this latter advantage apparent,
I have only to observe that in the hydro-thermic motor it is the heat of
the water which acts and not the compression of the steam, and that
one quart of air at 100 degrees "centigrade" contains the same quantity
of heat as 300 quarts of steam at the same temperature.
Having now described and ascertained the nature of my said Inven-
tion and in what manner the same is or may be permed, I claim as
'secured to me by the herein-before in part recited Letters Patent, the
use for working "Hydro-thermic Motive-power Engines," of the motive

page_text: power developed by the successive and alternate expansion and conden-
sation of any kind of liquid, this expansion and condensation being
produced by a liquid or gascous current, alternately and successively hot
and cold, which circulates by the action of the mechanical
set forth, in small tubes plunged into the aforesaid liquid.
means above
In witness whereof, I, the said Ferdinando Tommasi, have here-
unto set my hand and seal, this Nineteenth day of February,
in the year of our Lord One thousand eight hundred and seventy-
five.
PAUL PERROT,
JEAN BAPTISTE GIRARD.
FERDINANDO TOMMASI. (L.S.)