IMPROVEMENTS IN MACHINERY, APPARATUS AND PROCESSES FOR PRESERVING MEAT, MAKING ICE AND FOR REFRIGERATION GENERAL
Year: 1882

page_text: LETTERS PATENT to William Henry Northcott of Hatcham Ironworks,
Pomeroy Street New Cross London for an Invention of IMPROVEMENTS IN
MACHINERY, APPARATUS AND PROCESSES FOR PRESERVING MEAT, MAKING
ICE AND FOR REFRIGERATION GENERALLY
PROVISIONAL SPECIFICATION left by the said William Henry Northcott
at the Office of the Commissioners of Patents on the 24th August 1882.
WILLIAM HENRY NORTHCOTT of Hatcham Iron Works Pomeroy Street, New
Cross, London IMPROVEMENTS IN MACHINERY, APPARATUS AND PROCESSES FOR
PRESERVING MEAT, MAKING ICE AND FOR REFRIGERATION GENERALLY.
I construct my machine for producing cold air with one or more single acting
compressing cylinders, and one or more single acting expansion cylinders, bolted to
a bed plate in which are placed the water cooling tubes. I prefer to arrange the
cylinders vertically, and in this case the bedplate stands at the back of the
cylinders, and may be placed against a wall or bulkhead. The compressing cylinder
is water jacketed, and I lead the air issuing from it low down in the bedplate and
take it off to the expansion cylinder as high up as possible so that the water
deposited may be separated from the air and collected in suitable compartments
from which it is drawn off at intervals. In cases where the available height does
not allow of the vertical arrangement, I place the bedplate on its back, the cylinders
then being horizontal, I furnish the air chamber with a pressure gauge, safety
valve and drain cocks. The cooling tubes may be straight tubes as usual, but I
prefer to make them bent or return tubes, as these are easier kept tight and easier
removed for external cleaning. The air inlet valves of the compressing cylinder are
light mitre valves kept in place by springs. The outlet valves are of the same
description and covered by a single door. The expansion cylinder inlet valve is
formed of an india rubber ring kept in place by a circular wedge plate, this valve
being an improvement on Giffard's valve, Giffard's rubber ring however is used as
the valve seat and is not conveniently accessible. The inlet and outlet valves are
worked by cams.

page_text: In order to clear the passages leading from the expansion cylinder of snow
should they require it, I lead a small pipe from the compressed air chamber, or
direct from the compressing cylinder, to the said passages, which pipe has a cock,
by opening which a blast of compressed air may be sent through the expansion
cylinder passages.
I make the stroke of the expansion piston, both being of about the same diameter,
less than the stroke of the compressing piston, and I bring the expansion cylinder
closer to the crank shaft, so that with an equal proportional length of connecting
rod I am able to economise height or length, as otherwise the valve spindles of the
expanding cylinder, project beyond the length of the compressing cylinder. In
small machines where motive power is required, I combine the steam cylinder
with the compressing and expanding cylinders, but to prevent transfer of heat from
the steam cylinder to the air or cooling water I connect the steam cylinder
indirectly to the bedplate. I prefer however to drive the air cooling machine by
an engine working onto the same crankshaft but placed at a sufficient distance
from the machine to allow the latter to be enclosed in an insulated machine room,
so that no heat or escape steam from the engine is allowed to affect the atmosphere
drawn into the compressing cylinder. I also bring the waste air from the cooling
chamber back into the machine room, so that not only is most of this air used
again but the whole of the machine is kept at a lower temperature than the external
atmosphere. In some cases before allowing the waste air to escape into the machine
room, I cause it to pass through a series of pipes on the other side of which is the
compressed air going to the expansion cylinder. I send the compressed air around
the pipes and the waste air through them instead of the reverse as is usual, because
when the compressed air passes through the pipes ice is frequently formed in them
and the passage of the air is thereby impeded. I prefer to arrange the pipes
vertically and to lead the cold return air in at the top and out at the bottom round
the vessel so that the air may in rising cool the outside of the vessel also, a casing
being sometimes provided to lead the issuing air up in contact with the vessel.
The compressed air is led into this vessel at the bottom and is caused to impinge
against the cold tubes by a series of baffle or guide plates. Issuing at the top the
compressed air is led off to the expanding cylinder.
The small quantity of ice forming on the tubes when the machine is at work will
generally melt again when the machine stops, but I provide for melting it
occasionally by shutting the return air off from the interchanger and allowing it to
issue direct into the machine room. The water collecting in the bottom of the
vessel is drawn off at intervals.
In cases where the width of the machine has to be restricted I employ double
acting cylinders both for compressing and expanding the air and I employ piston
slide valves preferably placed underneath the cylinders for admitting and releasing
the air from all the cylinders, a single mitre valve between the pistons of the
compressing cylinder preventing the back flow of compressed air. The piston
valves are worked by an eccentric motion and the air is cut off in the expansion
cylinder by a mitre valve between the pistons of the main valve, which mitre valve
is worked by a cam or wiper.
In all cold air machines and especially those in which the expansion cylinder is
furnished with slide valves, it is difficult to start the machine against the full
pressure in the reservoir, or when the air is let off, against the vacuum in the
expansion cylinder. To obviate this I furnish the expansion cylinder with a small
self acting valve opening inwards and communicating either with the cold air
chamber or with the atmosphere. This valve prevents the formation of a vacuum
in the cylinder, and it also serves in some cases to adjust the temperature of the
cold air or to impregnate the air with a perfume or an antiseptic as hereafter
explained more fully.
For the conveyance of meat, milk and other perishable substances by rail I
construct a van to receive those substances and I place in the van a small machine
for compressing and expanding the air, such machine being driven by a belt or

page_text: other means from one of the axles of the van. I provide for the van going in
either direction by allowing the cams actuating the valves of the expansion cylinder
to slide round sufficiently on the shaft to give the valves the required motion
whether the machine is going forwards or backwards, and to obviate the necessity
of carrying cooling water I place a surface air cooler on the roof of the van, pro-
tecting such cooler from the sun's rays by a suitable covering or awning formed by
preference of louvre boards so inclined as to cause the current of air to impinge
directly against the cooling surface, and to allow also of rain falling on it.
I have found by experience that when cold air is conveyed any appreciable
distance from the machine producing it, the air quickly absorbs heat-even when
the pipe conveying it is large and well cleaded-and thereby loses its refrigerative
power. To obviate this loss by absorbtion and friction, also to save the expense
of lagging, and to enable smaller pipes to be used, when cold air is most conve-
niently applied at a distance from the motive power, I compress it in any ordinary
air compressor at a station convenient to the motive power and convey it under
pressure to the places where the cold air is required where I expand the compressed
air in any ordinary air engine, which may be employed in driving a fan for
diluting and increasing the volume of the cold air, or in doing any other required
work. Frequently it is sufficient to water jacket the compressing cylinder and to
allow the air to attain the atmospheric temperature by radiation during transit,
but the air may be further cooled by injection or surface cooling as is usual. I
prefer however, when required, to further cool the air by a surface cooler placed
as near as possible to the air engine. In either case I employ a separating vessel
to receive the air on leaving the compressing cylinder and another to receive it
from the main before it is expanded, to separate the moisture from the air before
expansion. These separating vessels, are vessels, preferably of considerable height,
of large plan sectional area, into the upper part of which the air enters and is
carried by a small pipe with a contracted mouth piece down into the vessel about
half the height of the vessel, the air being taken off again at the top of the vessel.
Compressed air has in many cases been conveyed long distances for the purpose of
obtaining motive power, but not for the purposes of refrigeration.
It is well known that the presence of moisture in the air drawn into air cooling
machines leads to loss of useful effect as a large part of the power exerted by the
air during expansion goes not to cool the air but to dry it by depositing and
congealing the contained moisture. When the cold air is employed for the pro-
duction of ice or for cooling liquids I obviate the above loss by utilising the dryness
of the air in aid of the process of freezing or cooling. To effect this I cause the air
after leaving the freezing chamber to pass over shallow vessels of water arranged
in successive order; and above one or more of these water vessels, preferably the
last of the series, I suspend a number of lamp wicks dipping into the water, pieces
of sponge or other absorbants amongst which the air passes. By these means the
air is not only thoroughly drained of its cold (so to speak) but is enabled to take
up its full complement of aqueous vapour before being sent into the atmosphere,
the evaporation so caused aiding very appreciably the refrigeration of the water.
I construct the chamber for freezing and cooling with two or more storeys, the
lower one containing the vessels of water to be frozen is carefully formed with
non-conducting walls, but the upper ones do not require so much insulation. The
air leaves the freezing space somewhat under the temperature at which water
freezes. It then passes upwards into the next space under and over a tank of
water therein placed. After cooling this water down to about 40° F. the air passes
into the next chamber where is placed a second water vessel into which dip the
capillary wicks and from which space the air leaves at about 60° F. and fully
saturated. In hot climates a third tank may be desirable but I have found one
freezing space and two cooling spaces give a good result at the ordinary atmospheric
temperatures of this country. The water is preferably fed into the upper tank
continuously in a fine shower near the point where the air leaves the chamber.
It is drawn off continuously or at intervals into the next lower tank from which

page_text: it is drawn off into the freezing vessels as required. The freezing chamber is
furnished with doors for removing and replacing the freezing vessels and when
clear ice is required I shake the freezing vessels by a suitable motion from outside.
In some cases I construct the upper chamber for receiving butter or meat to be
kept cool. And in hot climates I place a series of pipes in the space next the
freezing space and through these pipes pass the compressed air as it leaves the
water cooler and before it enters the expansion cylinder.
I have ascertained experimentally that meat and other substances may be
preserved at a temperature very moderate in comparison with those now employed
provided the atmosphere surrounding the substance be kept impregnated with
the vapour of chloralum, permanganate of potash or other antiseptic. I prefer to
use permanganate of potash dissolved in water because the solution imparts no
flavour or odour to the meat, and also because it is quite innocuous. And I pass
the air cooled and dried by expansion through a spray of the solution, or over or
amongst absorbants containing it. Or I expand the air in the expansion cylinder
down below the atmospheric pressure, the cylinder being in communication with a
vapourising vessel so that air is drawn into the expansion cylinder through the
spray or absorbant of the solution and mixed with air that has been cooled by
expansion the mixture of cold air and air so saturated with antiseptic vapour
being sent into the preserving chamber as usual. Or I blow air by a fan or blower
through a vapourising vessel and allow it to mix with air cooled by artificial
means, the mixture going then into the meat chamber, or the mixture may be
effected in the chamber itself. In some cases the air may be both cooled and
impregnated by the inductive action of a falling shower of solution, the air being
sent to the chamber and the unvapourised remainder of the solution pumped up
and used over again.
When ment is both preserved and frozen on board ship which is the case if there
is no freezing dépôt at the port of shipment I construct a separate freezing chamber
or preferably two for each machine employed in which the meat may be frozen
whilst hanging or packed in open order or as it were joint by joint. When frozen
hard in these chambers the joints may be removed and packed closely together as
by being thus frozen hard the joints are enabled to withstand superincumbent
weight without injury.
Sometimes instead of cooling the compressed air previous to expansion by passing
it over pipes containing the waste cold air as before described, I cool it and wash
out the moisture and other impurities by passing it through and in actual contact
with water cooled by the waste air. Such water may when necessary contain
permanganate of potash or other antiseptic in solution. The water may be kept
cool by the vessel containing it being placed bodily in the path of the waste cold
air, or a series of pipes may be placed only in such path, the vessel itself being
placed in the machine room. Or both systems may be used together.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said William Henry Northcott in the Great Seal Patent Office on the
24th February 1883.
WILLIAM HENRY NORTHCOTT of Hatcham Ironworks, Pomeroy Street, New
Cross, London IMPROVEMENTS IN MACHINERY, APPARATUS AND PROCESSES FOR
PRESERVING MEAT, MAKING ICE, AND FOR REFRIGERATION GENERALLY
I construct my machine for producing cold air with one or more single acting
compressing cylinders, and one or more single acting expansion cylinders bolted to
a bedplate in which are generally placed the cooling tubes. I prefer to arrange
the cylinders vertically, and in this case the bedplate stands at the back of the
cylinders, and may be placed against a wall or bulkhead. The compressing cylinder
is water jacketted, and I lead the air issuing from it, low down into the bedplate
and take it off to the expansion cylinder as high up as possible, so that the water
deposited may be better separated from the air, and collected in suitable compart-
ments whence it is drawn off at intervals. Figs 1. 2. 3. 4 show my vertical machine,
a is the compressing cylinder, b the expansion cylinder, c the bedplate forming also
the air reservoir, and containing the cooling tubes d. The air from the compressing
cylinder is led into the reservoir at e, and it follows the direction of the arrows.
The water deposited before cooling is drawn off at f, and that deposited after
k.
cooling at g. The crankshaft is lettered h, the flywheel i, and the water pump
In cases where the available height does not allow of the vertical arrangement, I
place the reservoir on its back, the cylinders then being horizontal, as shown at
Figs 5, 6, where a and b are the compressing and expanding cylinders, c is the
bedplate & the door covering the cooling tubes, e the pipe leading the air from the
compressing cylinder into the reservoir, ƒ and g drain cocks, h the crank shaft
and the flywheel. I furnish the air chambers also with a pressure gauge and
safety valve. The air inlet and outlet valves of the compressing cylinder, are light
mitre valves kept up to their seats by springs. The expansion cylinder inlet valve
is a mushroom valve Fig 7 with its seat formed of an india rubber ring a, easily
removeable when worn. Both expansion cylinder valves are actuated by cains m as
shown. In order to clear the expansion cylinder outlet ports of snow should they
require it, I lead a small pipe n from the air reservoir to the said passages, with a
cock by opening which a blast of warm compressed air may be sent through the
expansion cylinder passages so as to blow the snow therefrom. The expansion
cylinder outlet valve must of course be open, but the air blast may generally be
turned on without stopping the machine. I make the stroke of the expanding
piston in the case of the machines shown in Figs 1 to 7 less than the stroke of the
compressing piston, both pistons being about the same diameter. And I bring the
expansion cylinder closer to the crankshaft, so that with a connecting rod of the
same length in proportion to the stroke as I use for the compressing piston, I am
able to economise height or length, as otherwise the valve spindles of the expansion
cylinder project beyond the length of the compressing cylinder. In some cases I
combine the steam cylinder with the machine, but to prevent transfer of heat from
the steam cylinder to the air or cooling water, I connect the steam cylinder
indirectly to the bedplate as shown in Figs 1. 2. 5. 6. I prefer however to drive
the air cooling machine by an engine working onto the same crankshaft but
placed at a sufficient distance from the machine to allow of the latter being enclosed
in an insulated room so that no heat or escape steam is allowed to affect the
atmosphere drawn into the compressing cylinder. The steam cylinder arranged as
in Figs 5. 6 may be so separated from the machine, although not so completely as

page_text: if the engine were separate. I also bring the waste air from the cooling chamber
back into the insulated machine room, so that not only is most of this air used again,
but the machine itself works in an atmosphere cooler than the external atmosphere,
whilst at the same time the cold air is not allowed to come in contact with the steam
cylinder, or steam pipes. In some cases before allowing the waste air to escape into
the machine room, I cause it to pass through a series of pipes on the other side of
which is the compressed air going to the expansion cylinder. I send the com-
pressed air around the pipes and the waste air through them, instead of the reverse
as is usual, because when the compressed air passes through the pipes, ice is formed
in them, and the passage of the air is thereby impeded. I prefer to arrange the
pipes vertically, and to lead the cold return air in at the top and out at the bottom
round the vessel, so that the air in rising may cool the outside of the vessel also, a
casing being sometimes provided to lead the air up in contact with the outside of
the vessel. The compressed air is led into the vessel at the bottom and is caused
to impinge against the cold tubes by a series of baffle plates. Issuing at the top
the compressed air is led off to the expanding cylinder. In Fig 8 a is the inlet,
and bb the outlets for the cold waste air. The compressed air enters at c, and
leaves at d, after having been brought in contact with the outsides of the tubes by
the baffle plates e e.
The small quantity of ice forming on the tubes when the
machine is at work will generally melt again when the machine stops. But I
provide for melting it occasionally without stopping the machine by shutting the
return air off from the economiser, and allowing it to issue direct into the machine
room. _The water collecting in the bottom of the vessel is drawn off at intervals
at f. In some cases I employ double acting cylinders both for compressing and
expanding the air, with piston slide valves, preferably placed underneath the
cylinders, for admitting and releasing the fluids in all the cylinders, a single mitre
valve, or two as the case may be, preventing the back flow of compressed air into
the compressing cylinder. The piston valves are worked by an excentric, and the
air is cut off in the expansion cylinder, as also it may be in the steam cylinder, by
a mitre valve between the pistons of the main valve, which mitre valves are
worked by cams or tappits. This form of machine is shown in Figs 9, 10 where S
is the steam cylinder, C the compressing and E the expanding cylinders;
a, b, c are the three piston slidevalves placed underneath their respective cylinders
better to drain them. The steam and air are cut off for expansive working by
means of mitre valves worked from cams on the shaft d'as shown or by an
ordinary tappit motion. As the piston valve b would open to release the air before
it had attained the maximum pressure, I interpose an ordinary selfacting mitre
valve between the piston b and the air reservoir. The cooling tubes may be placed
in the baseplate or in a separate vessel.
In all cold air machines, and especially those in which the expansion cylinder is
furnished with a slidevalve, it is difficult to start the machine against the vacuum
forming in the expansion cylinder. To obviate this I furnish the expansion
cylinder with a small selfacting valve opening inwards into the cylinder, and
communicating with the cold air chamber or with the atmosphere. This valve
prevents the formation of a vacuum under the expansion piston, and it also serves
in some cases to adjust the temperature of the cold air delivered, or to impregnate
it with a perfume or antiseptic, as hereafter explained more fully.
For the conveyance of meat, milk or other perishable substances by rail I
construct a van with an insulated chamber to receive those substances, and I place
in the van a small machine a Figs 11, 12, 13 for producing the cold air, such
machine being driven by a belt b or other suitable means from the axle c of the
Van. I provide for the van going in either direction by constructing the cams
actuating the expansion cylinder valves so as to slide round sufficiently on the shaft
to give the valves the required motion whether the machine is going forward or
backward. But generally it is sufficient to provide one of the driving pulleys with
a ratchet clutch & communicating the motion in one direction only.
As in many
cases it is inconvenient to carry water for cooling the air, even although under

page_text: suitable arrangements the water may be used also for the locomotive, I place a
surface air cooler e on the roof of the van, protecting such cooler from the sun's
rays by an awning formed of louvre boards f, f, capable of being so inclined as to
cause the current of air formed by the motion of the van, to impinge directly
against the cooling surface, and to allow also of rain falling on the cooling tubes
I have found by experience that when cold air is conveyed any appreciable
distance from the machine producing it, the air quickly absorbs heat even when
the pipe conveying it is large and well cleaded, and thereby loses its refrigerative
power. To obviate this loss by absorbtion and friction, also to save the expense of
lagging, and to enable smaller pipes to be used when cold air is most conveniently
applied at a distance from the motive power, I compress it in any ordinary air
compressor at a station convenient to the motive power and convey it under
pressure to the places where the cold air is required where I expand the compressed
air in any ordinary air engine, which may be employed in driving a pump for
increasing the volume of the air, or in doing any other required work. Frequently
it is sufficient to water jacket the compressing cylinder and to allow the air to
attain the atmospheric temperature by radiation during transit, but the air may
be further cooled by injection or surface cooling as is usual. I prefer however,
when required to further cool the air by a surface cooler placed as near as possible
to the air engine. In either case I employ a separating vessel to receive the air on
leaving the compressing cylinder and another to receive it from the main before it
is expanded to separate the moisture from the air before expansion. The separating
vessels shown in Figure 14 are vessels preferably of considerable height of large
horizontal sectional area, into which at a the air enters, and is carried by a small
pipe with a contracted mouthpiece about halfway down the vessel, the air being
taken off again at b, the contained moisture is separated from the air and deposited
in the bottom of the vessel, from which it is drawn off at intervals at the orifice c.
Compressed air has in many instances been conveyed long distances for the purpose
of obtaining motive power, but not for the purposes of refrigeration. It is well
known that the presence of moisture in the air drawn into air cooling machines
leads to loss of useful effect, as a large part of the power exerted by the air during
expansion goes not to cool the air but to dry it by depositing and congealing the
contained moisture. When the cold air is employed for the production of Ice or for
cooling liquids I obviate the above loss by utilizing the dryness of the air in aid of
the process of freezing or cooling. To effect this I cause the air after leaving the
freezing chamber to pass over shallow vessels of water arranged in successive order;
and above one or more of these water vessels, preferably the last of the series, I
suspend a number of lamp wicks dipping into the water, pieces of sponge or other
absorbents amongst which the air passes. By these means the air is not only
thoroughly drained of its cold (so to speak) but is enabled to take up its full
complement of aqueous vapour before being sent into the atmosphere, the evaporation
so caused aiding very appreciably the refrigeration of the water. I construct the
Chamber for freezing or cooling with two or more storeys, figures 15, 16, the lower
one containing the vessels of water to be frozen (a a) is carefully formed of non-con-
ducting walls, but the upper ones do not require so much insulation. The air enters
the freezing chamber at b, and following the direction of the arrows passes amongst
the water vessels and leaves the freezing space at c somewhat below 32° F. It
then passes into the next space under and over a Tank of water therein placed.
After cooling this water down to about 40° F, the air passes by the orifice e into
the next Chamber, where is placed a second water vessel into which dip the capillary
wicks f, and from which space the air leaves at about 60° F fully saturated with
moisture. In hot climates a third tank may be desirable, but I have found one
freezing space, and two cooling spaces give a good result at the ordinary atmospheric
temperature of this country. The water is preferably fed into the upper tank
continuously in a fine shower near the point g where the air leaves the chamber.
It is drawn off continuously or at intervals by the cock h into the next lower tank
from which it is drawn off by the cock i into the freezing vessels as required. The

page_text: freezing chamber is furnished with doors k for removing and replacing the freezing
vessels a. a, and when clear ice is required I shake the freezing vessels by a suitable
motion from outside. In some cases I construct the upper chamber for receiving
butter or meat to be kept cool. And in hot climates I place a series of pipes in the
space next the freezing space, and through these pipes pass the compressed air as it
leaves the water cooler and before it enters the expansion cylinder, a separating
vessel as before described being placed between the cooling pipes and the expansion
cylinder.
I have ascertained experimentally that meat and other substances may be
preserved at a temperature very moderate in comparison with those now employed
provided the atmosphere surrounding the substance be kept impregnated with the
vapour of chloalum, permanganate of potash or other antiseptic. I prefer to use
chloralum or permanganate of potash dissolved in water because these solutions
impart no flavour or odour to the meat, and because also they are quite inocuous.
I pass the air cooled and dried by expansion through a spray of the solution, or
over or amongst absorbents containing it. Or I expand the air in the expansion
cylinder from a low pressure down below the atmospheric pressure, the cylinder
being in communication with a vaporizing vessel so that air is drawn into the
expansion cylinder through the spray or absorbent of the solution and mixed with
the air that has been cooled by expansion, the mixture of cold air and air so
saturated by antiseptic vapour being sent into the preserving chamber as usual.
Or I blow air by a fan or blower through a vaporizing vessel and allow it to mix
with air cooled by artificial means, the mixture going then into the meat chamber
as before. In some cases the air may be both cooled and impregnated by the
inductive action of a falling shower of the solution, the air being sent to the
chamber and the unvaporized remainder of the solution pumped up and used over
again.
When meat is both preserved and frozen on board ship, which is the case if
there is no freezing depot at the Port of shipment, I construct a separate freezing
chamber, or preferably two, for each Machine employed, in which the meat may
be frozen whilst hanging or packed in open order, or, as it were, joint by joint.
When frozen hard in these chambers the joints may be removed and packed closely
together one above the other, as by being thus frozen hard, the joints are enabled
to withstand superincumbent weight without injury. Sometimes instead of cooling
the compressed air previous to expansion by passing it over pipes containing the
waste cold air as before described, I cool it, and wash out the moisture or other
impurities by passing it through and in actual contact with water cooled by the
waste air. Such water may, when necessary, contain permanganate of potash or
other antiseptic in solution. The water may be kept cool by the vessel containing
it being placed bodily in the path of the waste cold air, or a series of pipes may be
placed only in such path, the vessel itself being placed in the Machine Room.
Having thus described my invention I have to state that I do not restrict myself
to the precise details herein described or illustrated but that what I believe to be
novel and claim as the special features of the invention are-
1. The arrangements of refrigerating machinery shown at Figs 1 to 6 inclusive,
combining the several improvements described.
2. The use of a small jet of comparatively warm compressed air for clearing the
expansion cylinder passages of snow as described.
3. The arrangements of refrigerating machinery in which the air cylinders (or
the expansion cylinder) are kept separate from the steam cylinder by being enclosed
in an insulated machine room into which is led the waste cold air substantially as
described.
4. The economiser or interchanger as described.
5. The refrigerating machine shown at Figs 9 and 10 and substantially as
described.
6 The vacuum valve to the expansion cylinder substantially as described.

page_text: 7. The locomotive refrigerating arrangements substantially as illustrated and
described.
8. The arrangements and apparatus for refrigerating at a distance from the
motive power substantially as described.
9. The refrigerating chamber and apparatus for utilising the dryness of the air
in aid of the process of refrigeration substantially as described.
10. Preserving meat by the combined refrigerating and antiseptic method
substantially as described.
In witness whereof I the said William Henry Northcott have hereunto set
hand and seal this 22nd day of February in the year of our Lord 1883
WITTTAM HENRY NORTHCOTT (LS)