Producing Ice, and in Liquid for the Purpose.
Year: 1884

page_text: Producing Ice, and in Liquid for the Purpose.
We, SAMUEL ALFRED VARLEY, of 2 Hamilton Road, Highbury Park, in the
County of Middlesex, Engineer, and WILLIAM AUGUSTUS GORMAN, of 187 West-
minster. Bridge Road, in the County of Surrey, Engineer, do hereby declare the
nature of said invention for "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR
REFRIGERATING AND PRODUCING ICE AND IN LIQUID FOR THE PURPOSE," to be as
follows:-
This invention has for its object improvements in machinery or apparatus for
refrigerating and producing ice. Such apparatus according to this invention is
constructed as follows:-
-
"
In a circular chamber that may be made in a metal casting are placed two
vulcanized India-rubber pipes having outside a coating of flexible material such as
canvas which will prevent them from stretching; these pipes rest against the back
or floor of the chamber being coiled round so as to form about two-thirds of a circle,
more or less, and as one of these pipes is coiled inside the other they forin parts of
circles of different diameters. The pipe of larger diameter will be hereinafter
called the "freezing pump" and both ends of this pipe are brought through holes
in the casting to the outside. The pipe of smaller diameter will be termed the
"air pump," one end of this pipe is brought through a hole in the casting to the
A tubular axle
outside, and the other terminates in the interior of the chamber.
having a metal cone near to one end of it passes through a conical hole bored
through the centre of the back of the chamber, the cone on the axle is ground to
fit the conical hole which forms an air tight bearing for the tubular axle. The
other end of this tubular axle runs in a second bearing attached by screws.to the
face of the chamber on the open side. A frame which carries rollers (conveniently
three) radiating from the centre and mounted at a suitable angle (i.e: when there
are three rollers an. angle of one hundred and twenty degrees) from one another is
mounted on the tubular axle and connected to it by a key or feather joint working
loosely in a slot in the frame and the frame is adjustable by a screw nut working
on a screw thread cut on a portion of the axle and is adjusted so that the rollers
compress the India-rubber pipes closing them completely at the compressed parts.
These rollers it is preferred to make of metal' coated with vulcanized india-rubber..
The two ends of the freezing pump and the one end of the air pump which pass

page_text: through to the outside of the casting are attached to metal pipes and air tight
joints are made between these pipes and the casting. The open side of the chamber
is also closed by a cap, the joint being made air tight by suitable packing. The
metal casting is mounted on a frame or bench and to enable motion to be com-
municated to the tubular axle without straining the conical air-tight bearing a
metal bridge which passes over and across the conical bearing is attached by screws
to the back of the chamber. Through this bridge and in a line with the tubular
axle a hole is bored; this hole forms the front bearing of a second axle the other
end of which passes through the interior of the tubular axle and runs in a bearing
mounted at the further end of it. A winch handle is attached to this second axle
which is called the driving axle by which it is revolved and the motion is com-
municated to the tubular axle by a key or pin attached to it which works in a
slot in the tubular axle.
'
One end of the freezing pump is connected through a series of tubular casings
termed the "condenser" to a "reservoir" which contains the freezing liquid. The
lower part of the "reservoir" is connected by a pipe to the entrance of the freezing
chambers which is termed the "charging pipe." The "freezing pump" the " con-
denser" "reservoirs" and "freezing chambers" form a closed circuit.
The charging pipe if made of metal has a stop cock which enables communication
between the lower part of the "reservoirs". and the freezing chambers.to be opened
or closed. It is preferred generally to make the "charging pipe" of vulcanized
india-rubber and to open and close the passage as desired by means of a jointed
lever which when depressed compresses the pipe and closes it.
The reservoir is nearly filled with the freezing liquid which must be one that
does not readily freeze, which boils at a low temperature and which does not
damage india-rubber; suitable liquids are either Proto-sulphide of Ammonium or
alcohol saturated with. ammonia gas and strong liquor ammonia or liquor ammonia
only. It is advantageous to use two or more freezing chambers. For the purposes:
of this description it will be assumed there are two-and that they are respectively
called "No.1" and "No. 2."
The freezing liquid by the action of gravity runs through the charging pipe into
the casing of N° 1 freezing chamber forcing forward any air there may be in the
casing and compressing it to a certain extent.
f
If the winch handle be now turned in the direction that the rollers roll over the
india-rubber pipes which form the "freezing" and "air pumps" from the freezing
chamber exit towards the condenser, the rollers in their passage force forward any
air there may be in the pipes in front of them leaving a vacuum in their rear for
the air behind to expand and rush into which in its turn is pushed forward by
the next succeeding roller. In the case of the "air pump" one end of which
terminates inside the air tight chamber of the casting and the other in the
atmosphere, the effect is to pump out any air there may be in the chamber and so
relieve the india-rubber pipes inside from atmospheric pressure. In the case of the
freezing pump the effect is to first pump out the air in the freezing chamber
casings and force it into the condenser and reservoir and then to pump the liquid
through.
"
When clear ice is required it will generally be advantageous to use conical metal
pails for freezing the water in. These pails have metal casings around them. The
lower part of the casing of one of these freezing chambers is connected to the
charging pipe." The upper portion of this casing is connected by a pipe termed
the "freezing exit," with the freezing pump. There is a branch pipe in the
freezing exit, which communicates through a "screening vessel" with the entrance
of the casing of No 2 freezing chamber. The exit pipe of this N° 2 freezing
chamber is joined to the "freezing exit "higher up and closer to the freezing pump.
Stop cocks suitably placed in these pipes enable the screening vessel and casing of
the N° 2 "freezing chamber to be included or cut out of the freezing pump circuit
as.desired, or the branch and freezing exit pipes may be made of india rubber and
communication opened or closed by depressing levers. The " screening chamber"
""

page_text: is a closed metal vessel having metal curtains depending from the top usually made
of metal tubes, arranged concentrically one inside the other. These depending
curtains drop into spaces between corresponding curtains attached to the bottom of
the vessel and proceeding upwards. The bottom of the "screening vessel" is
connected by a pipe of small diameter with the casing of No. 1 freezing chamber.
The water to be frozen is placed in the conical pails and light metal cones.
mounted on axles are placed in the centre of the pails, to which motion is given."
This can be conveniently done by an ordinary bottle jack or other suitable means.
To make clear ice the modus operandi is as follows:-The screening vessel and
No. 2, freezing chamber are cut out of the circuit of the freezing pump; and
communication is opened between the "reservoir" and the No. 1 freezing
chamber" casing. The winch handle is now revolved. The freezing liquid in the
exit pipe and No. 1. "freezing chamber" casing being now relieved from pressure
by the vacuum produced rapidly boils.
The ammonia in passing from the liquid to the gaseous state abstracts heat from
the freezing liquid which now rapidly falls below the freezing temperature of
water.
The greater part of the liquid in the freezing exit pipe is carried, mechanically
into the pump by the rapid ebullition which occurs. After allowing a little time
for this to take place, No. 2 freezing chamber is included in the freezing pump
circuit. The ammonia gas now passes through the centre of the top of the
screening vessel down and up between the curtains in the screening chamber, and
thence through the casing of No. 2. freezing chamber to the freezing pump, and any
liquid carried mechanically into the screening chamber becomes almost entirely
separated from the gas and runs back into the casing of No 1 freezing chamber.
The ammonia gas being of the same or nearly the same temperature as the liquid
it leaves, abstracts heat from the water in the pail of No 2 "freezing chamber" and
the water in the pail of No 1 "freezing chamber" is cooled and frozen by conduction
from the cooled down liquid in the casing.
The water freezes on the surfaces of the pails and any air or solid matter exuded
from the water by the act of crystallization is washed off the surface by the water'
in motion and so clear ice is produced.
The casings of the freezing chambers and also the "screening chambers" are
insulated by a good non-conductor of heat and to increase the cooling capacity of
the casing of No 2 freezing chamber, this casing may be filled with small pieces of
iron or copper or small glass beads or cannon lead shots, these expose a large
surface to the cool gas and become what I will for the sake of explanation call
reservoirs of cold which abstract the heat by conduction from the water in the pail
of this freezing chamber.
To indicate the temperature of the liquid in the freezing chamber a thermometer
is usually mounted in it and when the temperature rises which it will do after the
ammonia gas has been nearly all pumped out of the freezing chamber casing by
absorbing heat from the water in the pail, a fresh charge from the "Reservoir" is
introduced. Before introducing a fresh charge the screening vessel and No 2
freezing chamber casing are cut out of the circuit. After this has been done the
charging pipe is opened to let fresh liquid from the reservoir into the " freezing
chamber casing of N° 1 freezing chamber.
The spent liquid is pumped into the condenser and reservoir where it reabsorbs
the ammonia gas previously extracted from it. The "charging pipe". is again
closed and freezing operations can now be recommenced.
The ammonia gas, pumped into the condensers becomes condensed and the heat
abstracted from the "freezing chambers" and rendered latent by the ammonia
expanding into the gaseous condition is reproduced as sensible heat in the
condenser.
The greater part of this heat escapes into the atmosphere by radiation from
the surfaces of the condenser in its passage to the reservoir.
To assist the escape
of heat, the condenser way with advantage be constructed of a number of metal

page_text: casings, each casing being made by placing one tube within another the respective
diameters of which are such that only a small space separates them, the inner and
outer tubes of these casings are united together at the top and bottom by metal
rings soldered to the insides of the outer tubes and to the outsides of the inner
tubes and the casings are connected together by connecting tubes in such a way
that the ammonia in its passage from the pump exit to the Reservoirs has to pass
over the whole of the metal surfaces of these casings.
.
These casings may be placed in a trough and water circulated round them to
increase the rapidity of cooling.
When the apparatus is in work there is always a certain amount of pressure
in the interior of the Reservoir and the condenser, this pressure if kept within
moderate limits is an advantage as it assists to convert the latent heat of the
ammonia into sensible heat in which form it can be got rid of by radiation.
To prevent the pressure ever becoming unduly great the top of the reservoirs
may be closed with a Vulcanized India Rubber Cap or bag which allows expansion
to take place without greatly increasing the pressure.
:

page_text: арготощены іш паснегу or Apparatus for keirigerating and
Producing Ice, and in Liquid for the Purpose.
We, SAMUEL ALFRED VARLEY, of 2 Hamilton. Road, Highbury Park, in the
County of Middlesex, Engineer, and WILLIAM AUGUSTUS GORMAN, of 187 West-
minster Bridge Road; in the County of Surrey, Engineer, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
This invention has for its object improvements in machinery or apparatus for
refrigerating, and producing ice. Such apparatus according to this invention is
constructed as hereinafter described.
.
In the accompanying sheet of drawings the same letters refer to the same parts
in all the figures.
Fig. 1 is a general elevation, partly in section, shewing the arrangement and the.
connection between the different parts of the freezing apparatus. Fig. 2 is a front
view of the outer side of the.cap which closes the mouth of the chamber con-
taining the freezing and air pumps. Fig. 3 is a sectional view of the chamber.on
the line x. x, Fig. 2. Fig. 4 is a view of the inside of the chamber cap, shown in
Figs. 2 and 3 shewing the relative position of the freezing and air pumps. Figs. 5
and 6 are side and front views respectively shewing the construction of the clamps
used to close India-Rubber pipes hereinafter described. Fig. 7 shews a modified
arrangement that may be adopted for the condenser casings. Fig. 8 is a top
view of a grating placed between the top of the reservoir and the Vulcanized
India-Rubber cover which closes the reservoir.
In a circular chamber A. (Figs. 1, 2 and 3) that may be made in a metal casting,
are placed two vulcanized india-rubber pipes B and B¹ having outside a coating of
flexible material such as canvas, which will prevent them from stretching; these
pipes rest either against the back or floor of the chamber, or they may be
mounted upon the inner side of the metal cap A¹ forming the front of the chamber
as shown in the drawings. These pipes are coiled round so as to form about two-
thirds of a circle, more or less, and as one of these pipes is coiled inside the other
they form parts of circles of different diameters.
"
The pipe B of larger diameter will be hereinafter called the "freezing pump'
and both ends of this pipe are brought through holes C. C¹ in the casting A to
the outside. Only one of these holes can be seen in Fig. 3. The pipe of smaller
diameter will be termed the "air pump"; one end of this pipe is brought through
a bole C in the casting to the outside, and the other terminates as shown at B³,
Fig. 3, in the interior of the chamber or casting A. A tubular axle F having
a metal cone F¹ near to one end of it, passes through a hole, bored through the
centre of the cap A¹ of the chamber. This hole is preferably lined with suitable
anti-friction metal. The cone on the axle is ground to fit the hole so as to form an
air-tight bearing for the tubular axle. The other end of this tubular axle F runs
in a second bearing F at the opposite end of the chamber. A frame G which
carries rollers G³ (conveniently three) radiating from the centre and mounted at a

page_text: suitable angle (i.e.when there are three rollers at an angle of one hundred and
twenty degrees) from one another, is mounted on the tubular axle F and connected
to it by a key or feather joint (not-shown in the drawings) working loosely in a
slot in the frame G. The frame is adjustable by a screw nut G2 working on a screw
thread cut on a portion of the axle F and is adjusted so that the rollers compress
the freezing and air pumps B, B₁ closing them completely at the compressed
parts. These rollers it is preferred to make of metal (such as brass) coated with
vulcanized india-rubber. The two ends of the freezing pump B which pass through
to the outside of the casting, are attached to metal pipes D. D¹ whilst the one end
of the air pump B' which passes through to the outside of the casting A is attached
to a short pipe or nozzle piece D2 open to the atmosphere. Air tight joints are
made between the pipes D, D1, D2 and the cap A¹. The joint between the cap A¹-
and the casting A is made air tight by suitable packing. The metal casting A is
mounted on a frame or bench indicated in Fig. 3 at A², and to enable motion to be
communicated to the tubular axle F without straining the conical air-tight bearing,
a metal bridge H is employed which covers the centre of the cap A' and is attached
thereto by screws. Through this bridge and in a line with the tubular axle,
a hole is bored; this hole forms the front bearing of a second axle H¹, the other
end of which passes through the interior of the tubular axle F and runs in a
A winch handle H³ (Fig. 1) is
bearing H2 mounted at the further end of it.
attached to this second axle H', which is called the driving axle, by which it is
revolved, and the motion is communicated to the tubular axle F by a key or pin
(not shown on the drawings) attached to it and which works in a slot in the
tubular axle F.
•
to &
One end of the freezing pump B is connected through a series of tubular
casings I two only of which are shown in Fig. 1, termed the " condenser"
"reservoir" K which contains the freezing liquid. The lower part of the "reser-
voir" K is connected by a pipe L to the entrance of the casing m outside the first
freezing chamber M and which is termed the. "charging pipe." The "freezing
" the
" reservoir
" condenser,"
and "
pump
freezing chambers" form a closed
circuit. The charging pipe if made of metal has a stop cock L', which enables
communication between the lower part of the "reservoir" and the first freezing
chamber casing to be opened or closed. It is preferred generally to make the
charging pipe" L of vulcanized india-rubber and to open and close the passage
as desired by means of a jointed lever or clamp shown in Figs. 5 and 6.
"
The reservoir K is nearly filled with the freezing liquid, which must be one that
does not readily freeze, which boils at a low temperature, and which does not
damage india-rubber. Suitable liquids are either proto-sulphide of Ammonium
(Boyle's fuming liquid), or alcohol, either saturated with ammonia gas, or mixed
with strong liquor ammonia, or liquor ammonia only. It is advantageous to use
two or more freezing chambers M. M. For the purposes of this description it will
be assumed there are two and that they are respectively called "N° 1" and
"No 2:"
The freezing liquid by the action of gravity runs through the charging pipe L
into the casing m of No 1-freezing chamber, forcing forward any air there may be
in the casing. If the winch handle H³ be now turned in the direction of the
arrows (Fig. 4) so that the rollers G' roll over the "freezing". and "air pumps,"
the rollers in their passage force forward any air there may be in the .pumps in
front of them leaving a vacuum in their rear for the air behind to expand and rush
In the
into, which in its turn is pushed forward by the next succeeding roller.
case of the "air pump" one end of which terminates inside the air-tight chamber
of the casting A and the other in the atmosphere, the effect is to pump out any
air there may be in the chamber, and so relieve the india-rubber pumps inside from
atmospheric pressure. In the case of the freezing pump B the effect is to first
pump out the air in the freezing chamber casings and pipes in connection therewith
and force it into the condenser I and thence through the pipe I' to the reservoir K,
and afterwards to pump some freezing liquid through.

page_text: When clear ice is required it will generally be advantageous to make the freezing
chambers in the form of conical metal pails for freezing the water in. These pails
or chambers have metal casings m, m¹ round them as before stated. The lower
part of the casing m of one of these freezing chambers vizt N° 1 is connected to
the "charging pipe "L. The upper portion of this casing m is connected by a
pipe M with the freezing pump. There is a branch pipe from the pipe M³, which
communicates through a "screening vessel "O with the entrance to the casing m¹
of No 2 freezing chamber (M*). The exit pipe M³ of this Nº 2 freezing chamber is
joined to the "freezing exit " D higher up and closer to the freezing pump. Stop
cocks N, N', N2 (of which N. is a two way cock) suitably placed in these pipes
enable the screening vessel and casing of the N° 2 "freezing chamber' to be
included or cut out of the freezing pump circuit as desired, or the branch and
freezing exit pipes may be made of india-rubber and communication opened or.
closed by depressing levers or clamps as will be readily understood. The "screen-
ing chamber" O is a closed metal vessel having metal curtains O¹ depending from
the top and arranged concentrically one inside the other. These depending
curtains pass on either side of a corresponding curtain O attached to the bottom.
of the vessel and proceeding upwards. The bottom of the "screening vessel " is
connected by a pipe M³, of small diameter, with the casing m of N° 1 freezing
chamber.
The water to be frozen is placed in the conical freezing chambers M, M*, and
light metal cones P, mounted on axles, are placed within them and receive rotary;
motion. This can be conveniently done by an ordinary bottle jack, or other
suitable means not shown in the drawings.
To make clear ice the modus operandi is as follows:-
The screening vessel O and Ñ° 2 freezing chamber are cut out of the circuit of
the freezing pump by means of the stop cocks N and N³; and communication is
opened between the "reservoir" K and the N° 1 "freezing chamber" casing m by
means of the cock L. The winch handle H³ is now revolved. Freezing liquid
from the reservoir K is pumped into the casing of the N° 1 freezing chamber, and-
the connection between the reservoir and casing is closed. The winch handle is,
again turned the effect of which is to form a partial vacuum in the freezing,
chamber casing and its connections.
The freezing liquid then rapidly boils and the ammonia in passing from the
liquid to the gaseous state abstracts heat from the freezing liquid which now.
rapidly falls below the freezing temperature of water.
Any liquid there may be in the connections between the freezing chamber N° 1
and freezing pump is carried mechanically into the latter by the rapid ebullition
which occurs. After allowing a little time for this to take place, No 2 freezing
chamber is included in the freezing pump circuit by suitably operating the cocks N
and N. The ammonia gas now passes through the centre of the top of the
screening vessel O down and up between the curtains O¹ and O' in the screening
chamber, and thence through the casing m¹ of N° 2 freezing chamber to the
freezing pump, and any liquid carried mechanically into the screening chamber
becomes almost entirely separated from the gas and runs back into the casing of
N° 1 freezing chamber through the pipe M².
The ammonia gas being of the same or nearly the same temperature as the
liquid it leaves, abstracts heat from the water in N° 2 "freezing chamber" and
the water in N° 1 "freezing chamber" is cooled and frozen by conduction from the
cooled down liquid in the casing m. The water freezes on the surfaces of the
chambers and any air or solid matter exuded from the water by the act of
crystallization is washed off their surfaces by the motion of the water due to the
revolution of the cones P and thus clear ice is produced.
For the purpose of removing ice from the freezing chambers the upper bearing Q
of each metal cone P is removable to allow of the withdrawal of said cones.
The casings of the freezing chambers and also the "screening chambers" are
insulated by a good non-conductor of heat not shown in the drawings, and to

page_text: increase the cooling capacity of the casing of N° 2 freezing chamber, this casing
may be filled with small pieces of iron, or small glass beads, or common lead shots;
these expose a large surface to the cool gas and become what we will for the sake
of explanation call, reservoirs of cold, which abstract the heat by conduction from
the water in the pail of this freezing chamber.
To indicate the temperature of the liquid in the freezing chambers, ther-
inometers, may be mounted in each of them and when the temperature rises, which
it will do after the aminonia gas has been nearly all pumped out of the freezing
chamber casings by absorbing heat from the water in the freezing chambers, a
fresh charge of freezing liquid from the "reservoir" is introduced.. Before intro-
ducing such fresh charge the screening vessel O and N° 2 freezing chamber
casing m¹, are cut out of the circuit by suitably operating the stop cocks N and N³.
After this has been done the charging pipe L is opened to let fresh liquid from the
reservoir K into the casing m of N° 1 freezing chamber. The spent liquid is now
pumped into the condenser I and reservoir K where it re-absorbs the ammonia gas
previously extracted. from it. The "
charging pipe" is again closed and freezing
operations can now be recommenced.
The ammonia gas, pumped into the condenser becomes condensed and the heat
abstracted from the "freezing chambers" and rendered latent by the ammonia
expanding into the gaseous condition, is reproduced as sensible heat in the
condenser. Part of this heat escapes into the atmosphere by radiation from the
surfaces of the condenser in its passage to the reservoir. To assist the escape
of heat, the condenser may with advantage be constructed of a number of metal
casings, shown at 13, each casing being made by placing one tube within another
the respective diameters of which are such that only a small space separates them.
The inner and outer tubes of these casings are united together at the top and
bottom by metal rings I, soldered to the insides of the outer tubes and to the
outsides of the inner tubes and the casings are connected together by connecting
tubes in such a way that the ammonia in its passage from the pump to the
reservoir, as shown by the arrows, has to pass over the whole of the metal surfaces
of these casings. I is a pressure gauge which shews the amount of pressure in the
condenser. The casings may be placed in troughs J. J and water circulated round
them to further increase the rapidity of cooling.
In Fig. 7 is shown a double chamber R made of a metal casting, which may be
employed for condensing the ammonia gas. The bottom of this casting is closed by
a cap R¹ which forms an air-tight joint. S is a pipe cominunicating from the
outside of the casting through a channel in its lower part, with the interior of the
central chamber R². S¹ is an exit pipe passing from the outside into the central
chamber and reaching to within a short distance of the top of it, as shewn
in Fig. 7. Two, three, four or more of these double chambers R may be employed
to increase the cooling surface, the exit pipe S¹ of the first chamber being connected
to the pipe S of the second chamber and so on. The pipe S of the first chamber is
connected to the exit pipe D¹ of the freezing chamber and when the spent liquor
is pumped out of the freezing chamber casings and their connections it passes into
the central chamber R2 wherein it accumulates until it covers the mouth of the exit
pipe S¹, down which it passes into the central chamber R2 of the next condenser
and so on until it reaches the reservoir K. . The ammonia gas, when the machine
is in action, passes through the inlet and exit pipes of the condensers and becomes
condensed by the spent liquid in its passage. The outer chamber R³ is filled with
water which may be kept in a state of circulation to assist the cooling. T is a pipe
passing from the top of the central chamber R2 to the outside. V is a vulcanized
india-rubber pipe fitting tightly over the pipe T and which may be opened when
desired, by a clamp W to let any gas that may be in the chambers escape.
L
When the apparatus is in work there is always a certain amount of pressure in
the interior of the reservoir K and the condenser L To prevent this pressure ever
becoming unduly great the top of the reservoir is closed with a vulcanized india-.
:

page_text: rubber cap K' which allows expansion to take place without greatly increasing the
pressure.
This cap K is supported by a grating K₁ and is provided with a vulcanized
india-rubber pipe K³ which can be opened and closed by a clamp K*, (see Figs. 1
and 8).
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner the same is to be performed we declare that what
we claim is in machinery or apparatus for refrigerating and producing ice
1. The use in combination of a freezing pump and an air pump situated within
a closed chamber the arrangement being such that the air pump serves to reduce
the atmospheric pressure under which the freezing pump works, substantially as
described.
2. The combination with a reservoir containing freezing liquid, of an elastic
cap or cover the arrangement being such as to permit of expansion of gas within
the reservoir without greatly increasing the pressure therein, substantially as
herein before described.
3. The use as the freezing liquid of alcohol either saturated with ammonia gas
or mixed with liquor ammonia substantially as herein before described.
4. We claim the improved machinery or apparatus for refrigerating and pro-
ducing ice, constructed, arranged, and operating substantially as herein before
described with reference to, and shown in, Figs. 1, 2, 3, 4, 5, 6 and 8 of the
drawings.