IMPROVEMENTS IN REFRIGERATING AND FREEZING APPARATUS
Year: 1869

page_text: LETTERS PATENT to William Mort, of No. 155, Fenchurch Street, in
the City of London, Merchant, for the Invention of "IMPROVEMENTS
IN REFRIGERATING AND FREEZING APPARATUS."-A communication from
abroad by Thomas Sutcliffe Mort and Eugene Dominique Nicolle,
both of Sydney, in the Colony of New South Wales.
ealed the 18th January 1870, and dated the 23rd July 1869.
PROVISIONAL SPECIFICATION left by the said William Mort at the
Office of the Commissioners of Patents, with his Petition, on the
23rd July 1869.
I, WILLIAM MORT, of No. 155, Fenchurch Street, in the City of
London, Merchant, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN REFRIGERATING AND FREEZING APPARATUS," to be as
follows:-
This Invention has for its object improvements in refrigerating and
freezing apparatus. In order to obtain a considerable depression of
temperature a strong aqueous solution of ammonia is caused to evaporate
rapidly by exposing it to a low pressure, and the gas and weak ammonia

page_text: solution resulting from this action are recombined by exposing them to
pressure. The heat liberated in the recombination is carried off by a
stream of water.
The apparatus employed is shewn in the annexed Drawing.
A, double action pump fitted into a metallic piston composed of two
rings working smoothly within the barrel of the pump, and having an
inverted conical valve on one side of the piston; this valve is kept to
its face by a spiral spring recessed into the piston, and which gently
presses the valve against the seat. B, admitting slide valve working on
the upper part of the pump barrel; this valve when opened admits at
the same time both gas and liquid into the pump. C, delivering slide
valve working on the lower part of the pump barrel; this valve when
opened allows the partly combined gas and liquid to pass under the
force of the pump into the worm D in which it is cooled, whereby a
further combination of gas and liquid is induced. D, worm or spiral tube
receiving the partly combined gas and liquid from the pump. The
worm is immersed in a bath of cold water, which water is kept constantly
changed in order to carry away the heat given off during the combination
of the gas with the liquid. The extreme end of this worm leads into a
vessel called the "strong liquor vessel," into which by the pressure
exerted in the pump the contents of the worm are delivered through the
small holes with which the end of the worm is perforated. E, strong
liquor vessel surrounded by any good non-conductor; this vessel receives
the combined liquor and gas from the pump through the worm D, and is
made sufficiently strong to resist the working pressure; it is fitted
internally with a metallic coil tin being the material preferred for such
.coil. F, metallic coil fitted in the interior of the strong liquor vessel.
Through this coil the cooled weak liquor passes on its way from the
evaporator to the admitting slide valve B, imparting its reduced
temperature to the liquor contained in the strong liquor vessel, thereby
enabling the strong liquor to be further saturated with the gas under the
action of pressure and reduced temperature. G, feed pipe for supplying
the evaporator with concentrated liquor. H, evaporator, made herme-
tically tight, surrounded by any good non-conductor, and fitted with.
evaporating dishes fixed round the centre well; each dish having a
perforated overflow tube a little below the level of its edge. I, re-
frigerating well for freezing water or other substances. J, overflow pipe
leading the refrigerated exhausted liquor to the coil through which it

page_text: passes on its way to the entrance of the pump for combination with the
gas. The cooling or freezing of anything may be effected by forming a
connection with the overflow pipe at K and K. K, K', flange con-
nections. L, delivery pipe leading the weak liquor to the admitting
slide valve B after its refrigerating power has been made use of. M,
crank shaft for working the pump and cams, receiving its motion from
manual, steam, or any other source of power. N, N, slotted cams opening
and shutting the slide valves B and C; these cams are fixed on the
crank shaft M. O, O, fast and loose pulley keyed on to the crank shaft.
P, P, upright standard. Q, evaporating pipe connecting the evaporator
with the admitting slide valve B, and supplying the pump with gas.
R, gauge indicating the released pressure in the evaporator. R', gauge
indicating the pressure in the strong liquor. vessel. S, level gauge
shewing the quantity of strong liquor. T, water tank. U, pipe (with
regulating cock) to convey the water for refrigeration to the tank T.
V, discharge pipe for waste water.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Mort in the Great Seal Patent Office on
the 21st January 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
MORT, of No. 155, Fenchurch Street, in the City of London, Merchant,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of July, in the year
of our Lord One thousand eight hundred and sixty-nine, in the thirty-
third year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said William Mort, Her special licence that I,
the said William Mort, my executors, administrators, and assigns, or
such others as I, the said William Mort, 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 "IMPROVEMENTS IN REFRIGERATING AND
FREEZING APPARATUS," a communication to me from abroad by Thomas

page_text: Sutcliffe Mort and Eugene Dominique Nicolle, both of Sydney, in the
Colony of New South Wales, upon the condition (amongst others) that
I, the said William Mort, my executors or administrators, by an instru-
ment 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 William Mort, do hereby declare
the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement thereof, that is to say :-
This Invention has for its object improvements in refrigerating and
freezing apparatus.
Avoiding the beaten path of obtaining cold by the application of
Faraday's discovery of the liquefaction and subsequent gasification of
ammonia and other substances, for which Patents have been taken out
by Carré, Tellier, Reece, and others, this Invention simply avails of
the well-known affinity that ammonia has for water, whereby without
further mechanical aid than is afforded by a peculiarly, but simply
constructed pump, in combination with an equally simple apparatus,
the whole process of producing cold is carried on, and substances are
refrigerated or frozen without the necessity for any medium of transmission
other than the ammoniacal liquor itself. From the above statement and
the information which follows it will be seen that the process for which
I seek protection is one of liquefaction by affinity with the aid of slight
pressure, in contradistinction to the processes referred to of liquefaction
under pressure alone. The simplicity of the plan under which I work
enables me to employ it on any scale I may desire, from the small hand
apparatus for cottage use to the largest machine which can be required
in any process of congelation, and as from the absence of any material
*pressure the minimum amount of liability to get out of order is ensured,
a machine when once charged under ordinary care will not require any
further attention for a length of time, and then only from the con-
sequences contingent upon the usual wear and tear incidental to the
working of the pump, whilst it is always ready for action upon the
power required to work the pump being put in force.

page_text: Another point of great importance is the fact that the result obtained
from the working of my apparatus is a return in full of cold for power
exerted, which is not the case under the old plan, on account of the
waste of power in refrigerating the gas previous to liquefaction, and in
the cooling of the weak liquor before reabsorption.
The beautiful law of liquefaction by pressure has led many Inventors
to lay hold of ammonia as an agent for refrigerating purposes, but the
difficulties with which under that law the practical use of it is surrounded
have prevented its fulfilling its promise, and for commercial purposes
it may be said to have practically failed. The chief impediment to
success has been found in the high pressure required for the liquefaction
of the gas, especially in those climates where artificial cold is most
required, and where the natural temperature of the water forms but an
indifferent agent for carrying off the heat generated during reabsorption.
Moreover, under the plans referred to, in order to obtain cold at all
there is no choice but to exert a pressure sufficiently high to obtain
the absolute liquefaction of the gas, and which according to Faraday,
at a temperature of 60° will require a power of pressure equal to 6
atmospheres, rapidly increasing as the temperature rises, a condition
which presents a formidable difficulty on the practical working of the
process in the hot weather of summer or in warm climates, as above
stated. The cold obtained by the gasification of liquid ammonia is
doubtless very intense, but then it must be remembered that for all
ordinary purposes of useful application extreme temperatures are not
required, still, as just stated, under that plan there is no option but
to go to the full length of liquefaction to obtain cold at all.
By the new process herein described of affinity with water under
moderate temperature and slight pressure I am enabled to control the
working of the apparatus, and to produce whatever degree of cold I
may desire by simply regulating the strength of the liquor I may work
with, and the temperature at which I pass it from the strong liquor
vessel into the evaporator. (This application I especially claim on.
account of its novelty, simplicity, and general usefulness.) In addition.
to this the exceedingly light specific gravity of ammoniacal gas renders.
it so subtle under any amount of pressure as to make it difficult to.
retain in even the best constructed vessels, as it forces its way through
the very metal itself, the pores of which are opened by reason of the
action of the heat to which it is exposed.

page_text: The mode of lubricating the pump by the waste liquor after it has
performed its cold producing purposes on its passage with the gas to
the strong liquor vessel is a plan, which from its overcoming the
necessity for any other lubricator, and ensuring the perfect working
of the piston will be readily appreciated by those who are compelled
to work with dry gas alone, and is one that I claim special protection
for.
The consumption of fuel in heating the ammoniacal liquor in order to
liberate the gas, and in pumping the refrigerating water to carry off
the latent heat, in order to maintain as low a temperature as possible,
so as to render the liquefaction more easy is always a serious objection
wherever fuel is costly, whilst the water itself under some circumstances
is almost as costly as the fuel, owing to the large quantity required,
which cannot as a rule be again made use of.
Ammoniacal gas under high pressure is also exceedingly dangerous
to life, whilst all the contrivances in connection with the use of it
are extremely difficult of construction owing to their great complication,
and are liable to constant derangement, even when manufactured in
the best possible manner, whilst the difficulties of manipulation are
always greatest when the powers of the machine are in the most active
demand.
The "Australian refrigerating and freezing apparatus" herein described,
whilst it uses the same agent, viz., ammonia in solution, works under
a different law, and thereby avoids the dangers and difficulties which
attach to liquefaction under pressure alone, whilst it gives the fullest
amount of refrigerating power which the ammonia is of itself capable
of producing under any plan of application.
As already mentioned I avail of the affinity ammonia has for water,
and which under moderate pressure is so great that liquefaction takes
place most rapidly, thus pointing out the wondrous power of chemical
affinity, which as is well known liquefies gases, such as hydrogen, &c.,
gases, which so far as experiments have gone under pressure alone,
are incapable of liquefaction. It will thus be seen how by making
use of this affinity we avoid extreme pressure and obtain the power of
producing any degree of reduction of temperature by selecting the
pressure and temperature at which to work. No heat is employed,
liquefaction by the pressure of the gas itself being avoided by the sub-
stitution of a plan for mechanically mixing the gas and by reabsorption

page_text: through the affinity of gas for water under slight pressure and reduced
temperature, whilst all danger from explosion or escape of the gas is
overcome, either through the ammonia itself being always in combi-
nation with water, or else under released pressure. The slowness of
liquefaction (which no pressure can hasten except by the increase of
surface, which on a large scale is both impracticable and dangerous)
is also avoided by my new process, the reabsorption being enforced by
the action of affinity and slight pressure, as just explained.
My plan avoids the necessity for purging the machine, that is, the
removal of the stagnant liquor from the bottom of the vessels in which
under the old method gasification takes place, a most troublesome
interruption to the routine of the old apparatus, and involving much loss.
Again the common mode of applying the cold obtained by the
gasification of liquefied ammonia is by transmission through metallic
conductors to gaseous or liquid media, a course involving much waste
of power, as their own heat must be first extracted before they can be
made available as agents for imparting cold to other bodies. The plan
which is herein described possesses the great advantage of not requiring
any intermediate agent, the solution, following the law of liquids under
evaporation, first cooling itself is permitted to run under released
pressure from the evaporator as weak liquor at its lowest point of
temperature through pipes passing around the substances required to be
refrigerated, the solution returning by gravitation (cooling the liquor
in the strong liquor vessel on its way) to the entrance of the pump.
At this point the solution meets the gas from the evaporator, with
which under the law of affinity and the pressure exerted by the pump
it is thoroughly reunited and parting with its heat in passing through
a coil connected with the pump (both being immersed in a current of
water) is forced as strong liquor into the strong liquor vessel.. Upon
entering this vessel it is further cooled by exchanging temperature with
the liquor that is on its way from the refrigerating cylinder to the
pump, as above alluded to, and so rendered capable of absorbing a
further amount of gas, after which it is sent up by the pressure of
the gas (which always exerts a force equal to the pressure exerted by
the pump) to the evaporating chamber to be again evaporated, a course
which is continued so long as the pump is kept working.
Sectional Elevation.-A, double action pump fitted into a metallic
piston composed of two rings working smoothly within the barrel of the

page_text: pump, and having an inverted conical valve on one side of the piston;
this valve is kept to its face by a spiral spring recessed into the piston,
and which gently presses the valve against the seat. B, admitting slide
valve working on the upper part of the pump barrel; this valve when
opened admits at the same time both gas and liquid into the pump.
C₁
delivering slide valve working on the lower part of the pump barrel;
this valve when opened allows the partly combined gas and liquid to
pass under the force of the pump into the worm D, in which it is cooled,
whereby a further combination of gas and liquid is induced. D, worm
or spiral tube receiving the partly combined gas and liquid from the
pump; this worm is immersed in a bath of cold water, which water
is kept constantly changed in order to carry away the heat given off
during the combination of the gas with the liquid. The extreme end
of this worm leads into a vessel called the "strong liquor vessel," into
which by the pressure exerted in the pump the contents of the worm
are delivered through the small holes with which the end of the worm
is perforated. E, strong liquor vessel surrounded by any good non-
conductor; this vessel receives the combined liquor and gas from the
pump through the worm D, and is made sufficiently strong to resist
the working pressure; it is fitted internally with a metallic coil, tin
being the material preferred for such coil. F, metallic coil fitted in
the interior of the strong liquor vessel; through this coil the cooled
weak liquor passes on its way from the evaporator to the admitting
slide valve B, imparting its reduced temperature to the liquor contained
in the strong liquor vessel, thereby enabling the strong liquor to be
further saturated with the gas under the action of pressure and reduced
temperature. G, feed pipe for supplying the evaporator with con-
centrated liquor, and which for the purpose of controlling the admission
of the strong liquor into the evaporator is fitted with an index and
regulator; this feed pipe may or may not be perforated at its end; by
preference I use the perforated pipe so as to cause the liquor to be
minutely divided in order to increase its surface, thereby facilitating the
evaporation of the gas. H, evaporator made hermetically tight,
surrounded by any good non-conductor, and fitted with evaporating
dishes fixed round the centre well, each dish having a perforated
overflow tube a little below the level of its edge, in order to compel
the liquid to drop in a divided stream on each successive dish. By this
means is ensured as full an exhaustion of gas as possible from the liquid
under its released pressure and reduced temperature refrigerating as it

page_text: does at the same time the well I. I, refrigerating well for freezing water
or other substances; this well is firmly secured at the top and bottom
of the evaporator to which it forms a strong stay. If the freezing of
water be the purpose sought to be effected the number of well holes
may be increased at will. J, overflow pipe leading the refrigerated
exhausted liquor to the coil through which it passes on its way to the
entrance of the pump for combination with the gas; the cooling or
freezing of anything may be effected by forming a connection with this
overflow pipe at K and K'; the refrigerated exhausted liquor being
made to circulate in tubes through or around vessels or rooms of any
shape; or the same object may be attained if the liquor be made to
flow in, around, or through any confined vessel, the liquor in all cases
transmitting to the objects to be cooled or frozen the reduced tem-
perature it obtained by the evaporation of the gas in the evaporator.
The weak liquor may also be made available to cool any gaseous or
liquid media which may be employed to transmit reduced temperature.
K, K', flange connections to connect the flow of refrigerated weak
liquor with any room, apparatus, vessel, or substance requiring to be
cooled or frozen. L, delivery pipe leading the weak liquor to the
admitting slide valve B after its refrigerating power has been made
use of, when it is in readiness to receive through affinity and the action
of the pump the gas which is to regenerate its cooling force in the
evaporator. M crank shaft for working the pump and cams, receiving
its motion from manual, steam, or any other source of power. N, N¹,
slotted cams opening and shutting the slide valves B and C; these
cams are fixed on the crank shaft M. O, O', fast and loose pulley keyed
on to the crank shaft, the fixed pulley transmitting the motion, the
loose one serving for the stoppage of the machine when required.
P, P, upright standard supporting the evaporator H and receiving
the journals of the crank shaft M. Q, evaporating pipe connecting the
evaporator with the admitting slide valve B, and supplying the pump
with gas; R gauge indicating the released pressure in the evaporator.
R', gauge indicating the pressure in the strong liquor vessel. S, level
gauge shewing the quantity of strong liquor. T, water tank. U, pipe
(with regulating cock) to convey the water for refrigeration to the
tank T. V, discharge pipe for waste water.
Mode of Working the Machine.-Having described the various parts

page_text: .
remains to describe the mode of charging the same with the solution of
ammonia, and to explain the results obtained.
In constructing every part of the machine which may be liable to
come in contact with the ammonia, it is imperative that the following
metals should be used, viz., iron, cast or wrought, steel, lead, or tin,
avoiding copper, zinc, brass, or any of their alloys, as they are imme-
diately acted upon by the ammonia and soon destroyed, whilst the first-
named metals are not affected. The regulator G is provided with a
second stop-cock (not seen on the plan) branching out and underneath
the first, and leading into the perforated feed pipe close to its connection
with the evaporator. To this cock a flexible tube is fixed, and the
regulator G being shut the evaporator is now in connection with this
tube and subjected to the action of the pump. A vessel containing a
solution of ammonia of the specific gravity of 880, or stronger if the
external temperature will permit, is placed near the machine, and the
opposite end of the flexible tube is placed in it so as to reach nearly to
the bottom. The level gauge S having the trying cock (which is in line
with the glass tube) opened, and the bottom of the stop-cock next to
the strong liquor vessel closed, the stop-cock next the strong liquor
vessel is opened, and a free passage thereby effected between the cock
next the regulator G and the trying cock. The trying cock should be
provided with a flexible tube, also perforated at the end, and which end
should be immersed in a vessel containing cold water. The machine is
now ready to be charged. On applying power to the fixed pulley O the
pump A is set in motion. The slide valve B being opened by the motion
of the slotted cam N, a suction is thus caused into the evaporator H,
and the solution of ammonia placed in the vessel before alluded to,
passes up the flexible tube and is discharged into the first evaporating
dish, which on its being filled overflows on to the second, and so on,
until the whole are filled. The action of the pump is continued, and
the solution first filling the lower part of the evaporator overflows into
the coil F, through which it passes by the slide valve B into the pump,
from whence it is forced by the action of the pump through the worm D
into the strong liquor vessel E, the pump being kept in motion until
the liquor in the strong liquor vessel rises to the level indicated by the
level gauge. This level will be ascertained by first shutting the top
cock, and then the trying cock, and then opening the cock at the bottom
of the strong liquor vessel, and the vessels once charged the cocks so

page_text: remain. A gauge placed at the base of the evaporator, showing a few
inches above and below the level of the overflow pipe J will be found
convenient as a guide in charging, whilst a cock at the bottom of this
gauge will be of value for drawing off any liquor with which the
machine may be overcharged.
pressure
in
It will be seen by the description of this operation that the whole of
the atmospheric air which filled the apparatus has been expelled, and
if any ammoniacal gas should have followed the air it will have been
retained in the water placed under the trying cock. The machine being
thus charged the pump is again set in motion, and the following effect
takes place :-The pump on its downward stroke releases the
the evaporator by causing a suction of the ammoniacal gas evolved from
the solution down the pipe Q, which gas is driven by the pump through
the coil D into the strong liquor vessel E, wherein a pressure is soon
indicated by the gauge R¹, and a corresponding release of pressure shown
in the evaporator by the gauge R. When the proper quantity of gas has
been extracted from the evaporator, and which is ascertained by the
gauges remaining stationary, the regulator G is to be opened sufficiently
to feed the evaporator, and to maintain a fixed level of liquor in the
strong liquor vessel, which is effected by the pressure of the gas upon
the liquid in the strong liquor vessel. On delivering the strong liquor
into the evaporator no combination of gas takes place with the liquor in
the dishes, as the strong liquor has already been saturated to the full
extent of its capacity under the then pressure and the then reduced
temperature. On release of pressure the gas contained in the strong
liquor is rapidly evolved and continuously extracted by the pump. The
liquor, as it overflows the dishes and becomes colder by evaporation, first
imparts its reduced temperature to the tube or tubes in the, well I,
secondly runs through the overflow pipe J (having by that time reached
its coldest point), and after circulating around any apparatus that may
be connected at K, K', returns by gravitation to the pump at the slide
valve B, where it meets with the gas returning to the same point by Q.
The first combination therefore of gas and liquor takes place at the
bottom of the pump before the slide valve C opens, the second in the
coil D under the reduced temperature imparted by the current of cold
water at command, the third and last is effected in the strong liquor
vessel, where a still further reduced temperature is met with, the same.
being imparted by the weak liquor returning through the coil F to the

page_text: pump to be again saturated with gas. The slotted cams N, N¹, are
so set that they open the valves B and C in the following order,
videlicit B opens at the beginning of the downward stroke, and C only
opens after 10th of the stroke have been performed. The latter closes
immediately the piston reaches the end of the stroke, and B at the same
time closes also. On the upward stroke the conical valve of the piston
opens by the action of the piston and admits both gas and liquor into
the lower part of the pump barrel ready for the downward stroke to
effect the further combination by pressure, the requisite quantity of gas
for the next compression being extracted from the evaporator H by the
downward action of the piston, as before described..
Although I have only referred to the use of a single pump in my
description, of course any number of pumps may be applied; and again,
although I have described slide valves only as the means of obtaining and
releasing pressure, I do not abandon valves working by their own gravi-
tation, or by springs to retain them to their seats whatever shape they
may be; I use the slide valves by preference as they are not liable to
allow dirt to lodge between the seat and the valves during their function,
that being prevented by their being constantly in contact with the face.
Lastly, when the lowest temperature that can be obtained by the
solution of 880 has been reached if further reduction is necessary gas
alone is introduced by the second stop-cock in the manner before
described, except that the vessel containing the ammoniacal solution
is plunged into warm water, so as to make the liquor readily give off
the gas, and that the flexible gas pipe is made gas-tight to the entrance
of that vessel, and in such a manner as to allow only the gas to be
extracted by the action of the pump under the heat applied to the
solution. By this operation the pressure indicated by the gauge R¹
which had gradually fallen as the temperature was reduced in the
evaporator is now regenerated and a further reduction of temperature:
is the consequence. When temperatures of a low range are desired, to
obtain which, as just described, a further amount of gas is necessary,
a vessel in the form of a tender with the means of applying heat
externally should be attached to the machine at the branch cock under
the regulator G, as in the way herein-before shewn. This may be a
continued until the liquor in the machine has attained its greatest
power of saturation and becomes nearly absolute ammonia, and this
without increasing the first working pressure. The current of cold

page_text: water admitted by the pipe U must be kept constantly running so as to
maintain a temperature as low as the supply of water will allow.
For emptying the machine in case of need a stop-cock may be placed
on the overflow pipe J close to the connection flange K, and another
stop-cock on the evaporating pipe Q; the liquor can then be withdrawn
by the trying cock at the bottom of the level gauge S.
It will be observed that I claim among my special claims the
particular construction of the vessel which I use as a chamber for
containing articles required to be refrigerated or frozen when the space
afforded by the tube or tubes I is insufficient. This vessel (which would
be connected at K and K') is made of pipes, such as gas tubing of the
diameter required and bent to the required shape of the chamber to be
formed, care being taken that no obstruction is offered to the internal
circulation. This chamber I cover with calico or canvas, I then sur-
round the whole of the chamber or vessel with a casing of wood
leaving a space between the pipes and the case of about 1, to 2
inches, more or less. This space I fill in with substances which are
non-conductors, such as calcareous soap, paraffine, wax, &c., having a
melting point not below 130°. This arrangement is adapted for ships
or large stores, the connection with the machine being as already
described at K and K'.
Whilst I claim the general combination of the "Australian refri-
gerating and freezing apparatus," for all purposes in connection with
the obtainment of a reduction in temperature, I especially claim, -
First. The peculiar construction of the evaporator H, and its
position in reference to the other parts of the apparatus, whereby
the flow of cold liquor is by gravitation made to perform such important
functions.
Second. The peculiar construction of the pump A.
Third. The mode of bringing the gas and the weakened solution
into contact and into the pump.
Fourth. The particular mode of lubricating the piston of the pump
by the weak liquor, as herein explained.
Fifth. The arrangement of the strong liquor vessel E by which the
cold solution on its return from the refrigerating chamber by exchanging
temperature with the liquor next to be evaporated increases the power
of the strong liquor for absorbing gas, thus converting the vessel into

page_text: a reabsorber, whilst the pressure exerted by the gas therein constitutes
it a self-acting pump for forcing the strong liquor up to the evaporator.
Sixth. The arrangements by which I am able to control the pro-
duction of cold to any temperature I may require by regulating the
strength and temperature of the liquor with which I work.
Seventh. The mode of circulating the refrigerating liquor.
Eighth. The mode of refrigerating and freezing by the circulation of
the evaporated ammoniacal liquor itself and without the aid or inter-
vention of any other agent or medium.
Ninth. The particular arrangement and construction of the refri-
gerating chamber, and its direct connection with the cold producing
agent.
Tenth. The particular mode of protecting the refrigerating chamber
against the infiltration of heat.
In witness whereof, I, the said William Mort, have hereunto set
my hand and seal, this Nineteenth day of January, in the year
of our Lord One thousand eight hundred and seventy.