AN IMPROVED PNEUMO-HYDRAULIC MOTOR TO BE EMPLOYED AS A MOTIVE POWER
Year: 1872

page_text: LETTERS PATENT to Ferdinand Tommasi, of Paris, Department of
Seine, in the Republic of France, Gentleman, for the Invention of
"AN IMPROVED PNEUMO-HYDRAULIC MOTOR TO BE EMPLOYED AS A MOTIVE
POWER."
Sealed the 29th November 1872, and dated the 8th June 1872.
PROVISIONAL SPECIFICATION left by the said Ferdinand Tommasi at
the Office of the Commissioners of Patents, with his Petition, on
the 8th June 1872.
I, FERDINAND TOMMASI, of Paris, Department of Seine, in the
Republic of France, Gentleman, do hereby declare the nature of the
said Invention for "AN IMPROVED PNEUMO-HYDRAULIC MOTOR TO BE EMPLOYED
AS A MOTIVE POWER," to be as follows :—
The power of the pneumo-hydraulic motor consists in the tension and
rarefaction of the air produced by the weight of the water of the sea
raised by the tide in a recipient having two divisions or compartments
communicating with the sea.

page_text: The compressed air acts upon an apparatus motor with the same
degree of power as steam does, provided it be at an equal tension, and
the rarefied air by permitting the exterior air to exercise a pressure
proportionate to its rarefaction, enables it also in its turn to act on the
aforesaid apparatus with an equal degree of power.
The pneumo-hydraulic motor is essentially composed,―
Firstly. Of a reservoir by which the power is produced which is to the
pneumo-hydraulic motors what the boiler and its accessories arc to steam
engines.
Secondly. Of a motive apparatus constructed with some slight modi- 1
fications on the principle of a stationary steam engine.
The reservoir is divided into two compartments or divisions G and F,
see Sheet I. of the accompanying two Sheets of Drawing. Its lower
base is below the level of an average low tide at the syzygies A, its
upper base in its vertical part reaches the same level as the average high |
tides at the syzygies C, and its horizontal division M corresponds at the
point which serves as a base at the unit of height B.
In order to produce the various results of which I have spoken, the
reservoir must necessarily be entirely buried in the sand, and con-
sequently sheltered from the waves and storms. This reservoir may be
constructed either of masonry, hydraulic mortar, cast iron, or iron
plates, and may be of any form and at any distance from the sea, pro-
vided that it is placed at the aforesaid levels, and that the communi-
cating tube D is proportionally prolonged.
As soon as the sea reaches the point B the air contained in the com-
partment F not being able to find an outlet either by the tube H whose
orifice is submerged or by the tube I whose cock is closed, is compressed
to a degree of tension proportionate to the weight of the sea water. By
putting then this compressed air into communication with the feeding
tube of an apparatus similar to a steam engine and constructed in due
proportion both as regards the above tension and the amount of work
which it is desired to obtain, the apparatus will be put in movement and
will continue to work till the fall of the tide, that is to say, during a
period of about three hours. During this time the water which pene-
trates freely by the tube H into the compartment G (tho tube K being
in communication with the exterior air) fills the said compartment to

page_text: a level corresponding with the level of the sea. The cock of the tube K
is then closed, by which means the water in the compartment G is
prevented from escaping. As soon as the sea descends to the point B
the water, which remains as it were suspended in the compartment G,
5 rarefies by its weight the air which is found between it and the motive
apparatus, from which it results that by putting in communication the
feeding tube of the apparatus with the exterior air and its discharging
tube with the tube K, the weight of the exterior air bearing upon the
piston of the motive apparatus will be more or less considerable
according to the degree of rarefaction of the air in the tube K. This
rarefaction being proportionate to the weight represented by the height
of the water in the compartment G, and the height being the same as
that of the water which a short time before exercised its pressure (at
the rising tide) the pressure of the exterior air on the piston, and con-
sequently the degree of work which results from it, will be the same as
that of the compressed air and will continue so till the end of the
reflux, that is to say, for about three hours.
By the above means it would be possible to obtain perpetually about
three hours of work and three hours of rest. For those branches of
industry to which this intermittent work is not adapted it would be
necessary to construct à motive apparatus with two cylinders at right
angles, to which would be added a certain number of pumps worked
directly by its piston motors O and P, and the tides which occur during
the night and on Sundays would be utilized and be made to compress
by means of the said pumps the largest possible quantity of air and
force it into the recipient N, which is in reality nothing but the under-
ground part of the factory and which takes the name of the reserve
compartment. Whenever it is desired that the motive apparatus should
exercise its power during the three hours of rest above mentioned, it
will only be necessary to take away from the apparatus a cylinder and
all its pumps and put it in communication with the reserve compart-
ment, the compressed air of which will furnish the requisite power.
As the tubes K and. I may be indefinitely prolonged the work to be
obtained from the tides may be produced at any distance from the sea.
Should a company, formed ad hoc, undertake the expenses of instal-
ment and let out to manufacturers the motive force at so much the
cubic metre in the same way as is done with gas (the company in
this case would send to the different factories the compressed air con-
A 2

page_text: tained in a special reserve compartment which would be constantly
kept filled by means of pumps worked by the apparatus and pneumo-
hydraulic motors of the company), the manufacturers would be saved
the enormous expense of boilers, which have to be renewed every ten
years, the insurance premium both against fire and explosion, the
wages of the mechanics and stokers, the cost of coal, which will
necessarily become dearer in proportion as the mines become exhausted,
and they will have to pay only for the motive force of which they have
.
tained in a special reserve compartment which would be constantly
kept filled by means of pumps worked by the apparatus and pneumo-
hydraulic motors of the company), the manufacturers would be saved
the enormous expense of boilers, which have to be renewed every ten
years, the insurance premium both against fire and explosion, the
wages of the mechanics and stokers, the cost of coal, which will
necessarily become dearer in proportion as the mines become exhausted,
and they will have to pay only for the motive force of which they have
made effective use.
The cost of this motive force would be very moderate, as the pneumo- 1
hydraulic motors once established their maintenance would be essentially
gratuitous.
The motive force of the pneumo-hydraulic motor may be applied to
all kinds of industry, even to those where on account of the inflammable
nature of the substance to be worked it is impossible to use steam. It 1
is not affected by atmospheric variations such as arisc from decrease of
water in rivers and waterfalls, and moveover it can never fail in its
effects.
It is then useless to enlarge upon the advantages to be derived from
the use of the pneumo-hydraulic motor, and upon the important part
it is destined to play in commerce and in industrial pursuits.
The diagram Sheet I. represents a section of the sea shore reservoir
and reserve compartment.
A, level of average low tides during the syzygics; B, level of the
point which serves as a base of the unit of height; C, level of average
high tides during the syzygies; D, tube of communication between the
reservoir and the sea; E, reservoir; F, lower compartment; G, upper
compartment; H, tube of communication between the upper compart-
ment and the sea; I, tube of communication between the lower com-
partment and the feeding tube of the motor apparatus; K, tube of
communication between the upper compartment and the discharge tube
of the same apparatus; L, factory; M, horizontal division; N, reserve
compartment; O, cylinder with piston of the motor apparatus; P, pump
for compressing the air; Q; valve; R, cocks; S, the shore.
The only serious objection which could be raised against the appli-
cation of my pneumo-hydraulic motors to industrial purposes was that
there are but very few places in which they could be used. In fact it

page_text: must be admitted that it is somewhat difficult in practice to work
machines with an expansive force less than one atmosphere net, and
as the engines of my pneumo-hydraulic motors should begin to work
directly the tide is half way up. or down, it would be necessary to have
recourse to a tide with an average fall of twenty (20) metres (about
sixty (60) feet) to permit of the engines acting up to the tension of one
atmosphere net. Now tides of twenty (20) metres (about sixty (60)
feet) being the exception, few beaches would be found on which my
pneumo-hydraulic, motor might be used, unless special engines to work
at an average tension of half a net atmosphere could be constructed,
and it was probable that the construction of such machines would
prescut more or less difficulty.
Convinced of the justice of this. objection I have sought and found a
means of giving to thic engines of my pneumo-hydraulic motors a
tension double that which would have been communicated to them by
the height of the column of sea water available.
This method is as follows:-Given, for instance, a tide having a fall
of ten (10) metres (about thirty (30) feet). the height of the available
column of sea water, as well during flow as ebb, is of course but five
(5) metres (about fifteen (15) feet). A column of sea water of this
height can only compress the air during the rise of the tide to 0.5
atmosphere, and can only diminish the tension of the air which it rarefics
during the ebb by one half of the atmospheric tension. The working
piston consequently only receives from the rising tide a pressure of 0.5
of an atmosphere... But if on the other hand this piston instead of
meeting the resistance of the entire atmosphere, should encounter an
air the tension of which would be equal to only half of the atmospheric
tension, it is evident that the air compressed by the column of water of
five (5) metres, will in fact exercise on the piston a pressure of one (1).
atmosphere instead of 0.5.
In the same manner during the falling tide the rarefaction of the
air being equal to half the atmospheric tension, the pressure which the
motive power receives from the atmosphere can only be equivalent to
0.5 atmospheres. But if instead of being propelled by the atmosphere
the piston should be pushed forward by air compressed to half its
ordinary volume, it is also evident that the pressure really borne by the
piston would be that of one (1) atmosphere instead of 0.5.

page_text: Secondly. To put successively and alternately at each stroke of the
piston of the driving engine the tubes of the upper receivers in com-
munication with the discharge pipe of the cylinder of the driving engine,
allowing the tubes of the lower receivers to communicate with the
atmosphere.
This arrangement, whilst forcing the column of water to rarefy pro-
portionally to its height the air which in the cylinder of the driving
engine offers resistance to the movement of the piston, naturally re-
doubles the power which excrcises a pressure on the other side of the
said piston.

page_text: power.
DESCRIPTION OF THE DRAWING, SHEET II.
Figure 1 (considered as the transforming apparatus No. 1). A, level
of the fresh water in the upper and lower receiver of the transforming
apparatus; B, funnel with cock for the first filling of the apparatus ;
C, glass tube to indicate the level of the water in each receiver;
D, joint communicating with the joint N (Fig. 2); E, joint com-
municating with the joint U (Fig. 3); F, cocks for the first filling of
the apparatus; G, joint communicating with the joint M (Fig. 2);
H, joint communicating with the joint V, (Fig. 3); I, valve; J, valve.
Figure 1 (considered as the transforming apparatus No. 2). A, level
of the fresh water in the upper and lower receiver of the transforming
apparatus; B, funnel with cock for the first filling of the apparatus ;
C, glass tube to indicate the level of the water in each receiver; D, joint
communicating with the joint P (Fig. 2); E, joint communicating with
the joint X (Fig. 3); F, cocks for the first filling of the apparatus;
G, joint communicating with the joint Q (Fig. 2); H, joint com-
municating with the joint T (Fig. 3); I, valve; J, valve.
Figure 2. K, joint communicating with the joint Z (Fig. 4). L, tubes
communicating with the atmosphere; M, joint communicating with
the joint G of the transforming apparatus No. 1 (Fig. 1); N, joint
communicating with the joint D of the transforming apparatus No.1
(Fig. 1); O, joint communicating with the joint B' (Fig. 4), P, joint
communicating with the joint D of the transforming apparatus No. 2
(Fig. 1); Q, joint communicating with the joint G of the transforming
apparatus No. 2 (Fig. 1),
Figure 3. R, joint communicating with the joint Y (Fig. 4); S, joint
communicating with the joint C' (Fig. 4); T, joint communicating with
the joint H of the transforming apparatus No. 2 (Fig. 1); U, joint
communicating with the joint E of the transforming apparatus No. 1
(Fig. 1); V, joint communicating with the joint H of the transforming
5 apparatus No. 1 (Fig. 1); X, joint communicating with the joint E of
the transforming apparatus No. 2 (Fig. 1).

page_text: Figure 4. Y, joint communicating with the joint R (Fig. 3); Z, joint
communicating with the joint K (Fig. 2); A', manometers; B¹, joint
communicating with the joint O (Fig. 2); C³, joint communicating with
the joint S (Fig. 3); D', joint communicating with the tube issuing
from the lower compartment of the reservoir (compressed air); E¹, joint
communicating with the tube issuing from the upper compartment of
the reservoir (rarefied air); F³, entrance pipe of the slide valve of the
working cylinder; G³, discharge pipe of the slide valve of the working
cylinder.
I deem it superfluous here to enter into further minutiae, as on
reading the above description and examining the Figures of the accom-
panying Drawing it will be readily understood how when the tide rises
a part of the compressed air is changed into rarefied air, and when the
tide falls a part of the rarefied air becomes changed into compressed air,
and how this produces on the working piston a pressure double that
which it would have experienced by the simple effect of the weight of a
column of sea water of a height equal to half the total height of the
tide employed.
Thence follows the conviction that by means of my present improve-
ment the piston will always be in a position to work as well when the
tide is rising as when it is falling under a pressure equal to the weight
represented by a column of sea water of a height the same as the total
height of the above-mentioned tide.
And as tides of ten (10) metres high (about thirty (30) feet), which
with the present improvement represents the tension of one atmosphere
net exist on almost all shores, my pneumo-hydraulic motors can be
utilised almost everywhere.
It is scarcely necessary to add that the higher the tide, and conse-
quently the higher the degree of tension at which the machine will
work, the greater become the advantages derived from my pneumo-
hydraulic motors.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Ferdinand Tommasi in the Great Seal Patent
Office on the 7th December 1872..
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FERDINAND
TOMMASI, of Paris, Department of Seine, in the Republic of France,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighth day of June, in the year of
our Lord One thousand eight hundred and seventy-two, in the thirty-
fifth 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 Islands, and Isle of Man, an Invention for "AN IMPROVED
PNEUMO-HYDRAULIC MOTOR TO BE EMPLOYED AS A MOTIVE POWER,"
the
upon
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 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 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, reference being had to the accompanying
Sheet of Drawing and to the figures and letters of reference placed
thereon :-
The power
of the pneumo-hydraulic motor consists in the tension and
rarefaction of the air produced by the weight of the water of the sea
raised by the tide in a recipient having two divisions or compartments
communicating with the sca.

page_text: The compressed air acts upon an apparatus motor with the same
degree of power as steam does, provided it be at an equal tension; and
the rarefied air by permitting the exterior air to exercise a pressure
proportionate to its rarefaction enables it also in its turn to act on
the aforesaid apparatus with an equal degree of power.
DAC ACM apparatus in an equal degree of power.
The pneumo-hydraulic motor is essentially composed,-
Firstly. Of a reservoir by which the power is produced, which is to
the pneumo-hydraulic motors what the boiler and its accessories are to
steam engines.
Secondly. Of a motive apparatus constructed, with some slight
modifications, on the principle of a stationary steam engine.
The reservoir is divided into two compartments or divisions G and F,
see Figure 5 of the accompanying Sheet of Drawing. Its lower base
is below the level of an average low tide at the syzygies A; its upper
basc in its vertical part reaches the same level as the average high
tides at the syzygics C, and its horizontal division M corresponds at
the point which serves as a base at the unit of height B.
.
.
In order to produce the various results of which I have spoken the
reservoir must necessarily be entirely buried in the sand, and conse-
quently sheltered from the waves and storms.
This reservoir may
be constructed either of masonry, hydraulic mortar, cast-iron or iron
plates, and may be of any form and at any distance from the sea,
provided that it is placed at the aforesaid levels and that the com-
municating tube D is proportionally prolonged.
As soon as the sea reaches the point B the air contained in the
compartment F not being able to find an outlet either by the tube H,
the orifice of which is submerged, or by the tube I, of which the cock
is closed, is compressed to a degree of tension proportionate to the
weight of the sea water. By putting then this compressed air into
communication with the feeding tube of an apparatus similar to a steam
engine, and constructed in due proportion, both as regards the above
tension and the amount of work which it is desired to obtain, the
apparatus will be put in movement, and will continue to work till the
fall of the tide, namely, during a period of about three hours. During
this time the water, which penetrates freely by the tube II into the a

page_text: compartment G (the tube K being in communication with the exterior
air), fills the said compartment to a level corresponding with the level
of the sca. The cock of the tube K is then closed, by which means the
As soon as
water in the compartment G is prevented from escaping.
the sea descends to the point B the water, which remains as it were
suspended in the compartment G, rarefies by its weight the air which
is found between it and the motive apparatus, from which it results that
by putting in communication the feeding tube of the apparatus with
exterior air and its discharging tube with the tube K, the weight of the
exterior air bearing upon the piston of the motive apparatus will be
more or less considerable, according to the degree of rarefaction of the
air in the tube K. This rarefaction, being proportionate to the weight
represented by the height of the water in the compartment G, and the
height being the same as that of the water which a short time before
exercised its pressure (at the rising tide), the pressure of the exterior
air on the piston, and consequently the degree of work which results
from it, will be the same as that of the compressed air, and will
continue so till the end of the reflux, namely, for about three hours.
By the above means it would be possible to obtain perpetually about
three hours of work and three hours of rest. For those branches of
industry to which this intermittent work is not adapted it would be
necessary to construct a motive apparatus with two cylinders at right
angles, to which would be added a certain number of pumps worked
directly by its piston motors O and P, and the tides which occur
during the night and on Sundays would be utilized, and be made to
compress by means of the said pumps the largest possible quantity of
air, and force it into the recipient N, which is in reality nothing but
the underground part of the factory, and which takes the name of the
reserve compartment. Whenever it is desired that the motive apparatus
should exercise its power during the three hours of rest above mentioned,
it will only be necessary to take away from the apparatus a cylinder
and all its pumps, and put it in communication with the reserve
compartment, the compressed air of which will furnish the requisite
power.
As the tubes K and I may be indefinitely prolonged, the work to
idas max he produced at any distance from the

page_text: Should a company, formed ad hoc, undertake the expenses of instal-
ment, and let out to manufacturers the motive force at so much the
cubic metre, in the same way as is done with gas (the company in
this case would send to the different factories the compressed air
contained in a special reserve compartment, which would be constantly
kept filled by means of pumps worked by the apparatus and pneumo-
hydraulic motors of the company), the manufacturers would be saved
the enormous expense of boilers, which have to be renewed every ten
years, the insurance premium both against fire and explosion, the wages
of the mechanics and stokers, the cost of coal, which will necessarily
become dearer in proportion as the mines become exhausted, and they
will have to pay only for the motive force of which they have made
effective use.
The cost of this motive force would be very moderate, as the pneumo-
hydraulic motors once established their maintenance would be essentially
gratuitous.
The motive force of the pneumo-hydraulic motor may be applied to
all kinds of industry, even to those where, on account of the inflammable
nature of the substance to be worked, it is impossible to use steam. It
is not affected by atmospheric variations, such as arise from decrease of
water in rivers and waterfalls, and moreover it can never fail in its
effects.
It is then useless to enlarge upon the advantages to be derived from
the use of the pneumo-hydraulic motor, and upon the important part
it is destined to play in commerce and in industrial pursuits.
On the accompanying Sheet of Drawing Figure 5 represents a section
of the sea shore reservoir and reserve compartment.
A, level of average low tides during the syzygies; B, level of the
point which serves as a base of the unit of height; C, level of average
high tides during the syzygies; D, tube of communication between the
reservoir and the sca; E, reservoir; F, lower compartment; G, upper
compartment; H, tube of communication between the upper compart-
ment and the sea; I, tube of communication between the lower com-
partment and the feeding tube of the motor apparatus; K, tube of
communication between the upper compartment and the discharge tube 3
of the same apparatus; L, factory; M, horizontal division; N, reserve

page_text: compartment; O, cylinder with piston of the motor apparatus; P, pump
for compressing the air; Q, valve; R, cocks; S, the shore.
The only serious objection which could be raised against the applica-
tion of my pneumo-hydraulic motors to industrial purposes was that
there are but very few places in which they could be used. In fact it
must be admitted that it is somewhat difficult in practice to work
machines with an expansive force less than one atmosphere net, and as
the engines of my pneumo-hydraulic motors should begin to work
directly the tide is half way up or down it would be necessary to have
recourse to a tide with an average fall of 20 metres (about 60 feet)
to permit of the engines acting up to the tension of one atmosphere
net.
Now tides of 20 metres (about 60 feet) being the exception, few
beaches could be found on which my pneumo-hydraulic motor might be
used unless special engines to work at an average tension of half a net
atmosphere could be constructed, and it was probable that the construc-
tion of such machines would present more or less difficulty.
Convinced of the justice of this objection I have sought and found
a means of giving to the engines of my pneumo-hydraulic motors a
tension double that which would have been communicated to them by
the height of the column of sea water available.
This method is as follows:-Given, for instance, a tide having a fall
of 10 metres (about 30 feet) the height of the available column of sea
water, as well during flow as ebb, is of course but 5 metres (about
15 feet).
A column of sea water of this height can only compress the air during
the rise of the tide to 0.5 atmosphere, and can only diminish the tension
of the air which it rarefies during the ebb by one half of the atmospheric
tension.
The working piston consequently only receives from the rising tide
a pressure of 0.5 of an atmosphere.
But if, on the other hand, this piston, instead of meeting the resist-
ance of the entire atmosphere, should encounter an air the tension
of which would be equal to only half of the atmospheric tension, it is

page_text: The function of these two apparatuses is to transform,―
Firstly. During the rising tide a part of the compressed air from
the reservoir into rarefied air:
Secondly. During the ebb a portion of the rarefied air from the
reservoir into compressed air.
To do this it is necessary simply during the flow,—
Firstly. To cause successively and alternately at each. stroke of the
piston of the working machine a portion of the compressed air of the
reservoir to penetrate the tubes of the lower receivers of these apparatuses,
allowing the tubes of the upper receivers to communicate with the
atmosphere.
This compressed air forces the water contained in these apparatuses
to rise in the upper receivers to a height proportioned to its tension.
Secondly. To put successively and alternately at each stroke of the
piston of the driving engine the tubes of the upper receivers in com-
munication with. the discharge pipe of the cylinder of the driving
engine, allowing the tubes of the lower receivers to communicate with
the atmosphere.
This arrangement, whilst forcing the column of water to rarefy pro-
portionally to its height the air which in the cylinder of the driving
engine offers resistance to the movement of the piston naturally
redoubles the power which exercises a pressure on the other side of the
said piston.

page_text: This arrangement whilst forcing the column of water to compress in
proportion to its height the air which in the cylinder of the driving
engine must propel the piston, naturally redoubles the effect of the rare-
faction produced on the other side of the said piston.
The
The height of each apparatus should be calculated in such a manner
that the distance between the two levels A (Fig. 1) be such that the
column of fresh water which results from it may have the same weight.
as a column of sea water of a height equal to half the total height of
the tide which is employed. The volume of air which has to penetrate
alternately into the upper and lower receivers is equal to twice the
volume of the cylinder of the driving or principal machine.
diameter and height of the upper and lower round receivers of the said
apparatus should be calculated so that the capacity of each receiver may
be six times more than the capacity of the cylinder of the driving
engine. It is moreover advisable to give these receivers the least
possible height at the expense of a diameter naturally greater, so as
to diminish as far as possible the up-and-down movement of the water
contained in these apparatus.
The two valves I and J should be so placed that their weight when
the air has to raise them may be almost nil. This arrangement not
only permits of the compressed air from the reservoir profiting (when it
forces the water to rise in the transformer) by the rarefied air remaining
in the upper part of this latter, but it also allows the rarefied air, which
should in its turn force up the water in the said transformer, to profit
by such compressed air as may remain in the lower part. This naturally
produces a saving in the consumption of the compressed and rarefied
air of the reservoir. The two transforming apparatuses may be made
of copper, bronze, or cast iron.
Figure 2 represents a horizontal section of the slide valve designed
to distribute to the two transforming apparatus the compressed and
rarefied air of the reservoir. Figure 3 represents a horizontal section
of the cylindrical slide valve destined to distribute to the slide valve
of the working cylinder the air compressed and rarefied by the two
transforming apparatus. These two slide valves having to follow the
same movement as the distributing slide valve of the working cylinder,
will be moved by the same eccentric. The function of these two slide

page_text: valves is to communicate to the two transforming apparatuses all the
movements necessary for the accomplishment of their work.
Figure 4 represents, firstly, the distributing slide valve of the working
cylinder; secondly, the horizontal section of the cylindrical piston slide
valve intended to cause the escape of the compressed air of the working
cylinder during the last tenth of the stroke of the piston of the latter.
This slide valve will be moved by a special eccentric, to which one-tenth
of a stroke will be given in advance of the other eccentric. The
function of this slide valve is to permit the rarefied air either of the
reservoir or of the transforming apparatus to rarefy at each stroke of
the piston a smaller volume of air, and consequently to economise a
nant of its nomor
Figure 1 (considered as the transforming apparatus No. 1). A, level
of the fresh water in the upper and lower receiver of the transforming
apparatus; B, funnel with cock for the first filling of the apparatus; C,
glass tube to indicate the level of the water in each receiver; D, joint
communicating with the joint N (Fig. 2); E, joint communicating with
the joint U (Fig. 3); F, cocks for the first filling of the apparatus; G,
joint communicating with the joint M (Fig. 2); H, joint communicating
with the joint V (Fig. 3); I, valve; J, valve.
Figure 1 (considered as the transforming apparatus No. 2). A, level
of the fresh water in the upper and lower receiver of the transforming
apparatus; B, funnel with cock for the first filling of the apparatus; C,
glass tube to indicate the level of the water in each receiver; D, joint
communicating with the joint P (Fig. 2); E, joint communicating with
the joint X (Fig. 3); F, cocks for the first filling of the apparatus; G,
joint communicating with the joint Q (Fig. 2); H, joint communicating
with the joint T (Fig. 3); I, valve; J, valve.
Figure 2. K, joint communicating with the joint Z (Fig. 4); L, tubes
communicating with the atmosphere; M, joint communicating with
the joint G of the transforming apparatus No. 1 (Fig. 1); N, joint
communicating with the joint D of the transforming apparatus No: 1
(Fig. 1); O, joint communicating with the joint B¹ (Fig. 4); P, joint
communicating with the joint D of the transforming apparatus No. 2,

page_text: (Fig. 1); Q, joint communicating with the joint G of the transforming
apparatus No. 2 (Fig. 1).
Figure 3. R, joint communicating with the joint Y (Fig. 4); S, joint
communicating with the joint C' (Fig. 4); T, joint communicating with
the joint of the transforming apparatus No. 2 (Fig. 1); U, joint
communicating with the joint E of the transforming apparatus No. 1,
(Fig. 1); V, joint communicating with the joint H of the transforming
apparatus No. 1 (Fig. 1); X, joint communicating with the joint E of
the transforming apparatus No. 2 (Fig. 1).
Figure 4. Y, joint communicating with the joint R (Fig. 3); Z, joint
communicating with the joint K (Fig. 2); A¹, manometers; B³, joint
communicating with the joint O (Fig. 2); 0¹, joint communicating
with the joint S (Fig. 3); D', joint communicating with the tube issuing
from the lower compartment of the reservoir (compressed air); E¹,
joint communicating with the tube issuing from the upper compart-
ment of the reservoir (rarefied air); F¹, entrance pipe of the slide valve
of the working cylinder; G³, discharge pipe of the slide valve of the
working cylinder.
I deem it superfluous here to enter into further minutiæ, as on reading
the above description, and examining the Figures of the accompanying
Drawing, it will be readily understood how when the tide rises a part
of the compressed air is changed into rarefied air, and when the tide
falls a part of the rarefied air becomes changed into compressed air,
and how this produces on the working piston a pressure double that
which it would have experienced by the simple effect of the weight of a
column of of sea water of a height equal to half the total height of the
tide employed.
Thence follows the conviction that by means of my present improve-
ment the piston will always be in a position to work as well when the
tide is rising as when it is falling under a pressure equal to the weight
represented by a column of sea water of a height the same as the total
height of the above-mentioned tide.
And as tides of 10 metres high (about 30 feet) which with the present
improvement represents the tension of one atmosphere net exist on
almost all shores, my pneumo-hydraulic motors can be utilised almost
everywhere.

page_text: It is scarcely necessary.to add that the higher the tide and consc-
quently the higher the degree of tension at which the machine will
work, the greater become the advantages derived from my pneumo-
hydraulic motors.
In witness whereof, I, the said Ferdinand Tommasi, have here-
unto set my hand and seal, this Third day of December, in
the year of our Lord One thousand eight hundred and seventy-
O JEAN BAPTISTE GIRARD,
EDOUARD DESCHAMPS,
83bis, Rue Lafayette.
FERDINAND TOMMASI. (L.S.)