IMPROVEMENTS IN COMBINED GAS APPARATUS TO BE USED ON BOARD SHIP
Year: 1872

page_text: LETTERS PATENT to John Thomas Brown Porter, of the City of
Lincoln, Civil Engineer, for the Invention of "IMPROVEMENTS IN
COMBINED GAS APPARATUS TO BE USED ON BOARD SHIP."
Sealed the 18th February 1873, and dated the 21st September 1872.
PROVISIONAL SPECIFICATION left by the said John Thomas Brown
Porter at the Office of the Commissioners of Patents, with his
Petition, on the 21st September 1872.
I, JOHN THOMAS BROWN PORTER, of the City of Lincoln, Civil
Engineer, do hereby declare the nature of the said Invention for "Im-
PROVEMENTS IN COMBINED GAS APPARATUS TO BE USED ON BOARD SHIP," to be
as follows:
This Invention relates to a peculiar combination and arrangement of
combined gas apparatus intended for use on board ship, and consists in
combining together a number of vertical conical retorts which may be
set singly or in pairs in circular ovens, so that one may be used in the
daytime and two or the whole three at night, each pair being heated
from one furnace, the flues from whịch make a complete circuit round

page_text: the retorts by means of a spiral partition in the oven. In the upper end
of these retorts are two discs, the upper one being concave on its upper
face and perforated, and the lower one convex on its upper face. These
discs are intended to disperso the oil from which the gas is manufactured
over the inner sides of the retorts, and are fed with oil and a small pro-
portion of water or other liquid from cisterns and through funnels and
syphon pipes fixed to the lids of the retorts, which lids are fitted with
an effective fastening consisting of hinged bolts working in slots in the
flanges of the lids. These bolts carry nuts which being slightly loosened
allow the bolts to fall down and release the lid when required for cleaning
the retorts. The retorts are of such a peculiar shape, being widened at
the top and forming a bulge round the side for the oil to fall upon on
the inside and for the flame to strike against on the outside, that how-
ever heavily the ship may roll or pitch, the oil flowing from the lower
disc must of necessity fall upon the said widened and heated surface.
The two discs have a large opening or short tube in their centre to afford
passage for the gas as it rises from the heated surface of the retorts.
Outlet pipes are attached to the top and bottom of each retort, the upper
one being for the gas and the lower one fitted with a cleaning cap and
having a drip box attached beneath it for receiving any excess of oil not
gasefied in the retort (should the latter through inattention not be
sufficiently heated before the oil is turned on). This excess is discharged
from the drip box when necessary through a draw-off cock into a bucket,
thus dispensing with the usual dip cisterns on the floor.
The upper
outlet is bent downwards before entering the main pipe in front of the
retort.stack, thus preventing any refuse which may accumulate in this
pipe from flowing back into the retort, the said refuse being removed by
draw-off cocks at each end of the main pipe. The lower outlet or tail
pipe forms an obtuse angle with the retort, thereby enabling any oil
which may have found its way to the bottom of the retort a better chance
of flowing away when the ship lays over at an angle.
The whole of the retort stack is enclosed in plates of cast iron, ribbed
on the inside so as to leave an air space between the brickwork and the
plates which prevents the radiation of heat from the stack, and thus
economises the fuel for the furnaces, and at the same time. removes the
danger which might be caused to the vessel if the heat were not thus
confined; consequently the stack can be fixed in a much smaller space
than it otherwise could be. These plates are so arranged that any of the

page_text: retorts can be removed and a new one substituted without interfering
with the other parts of the stack, and so as to give easy access to any of
the flues or ovens for cleaning.
The washer and condenser consists of two hydraulic boxes, each of
which is divided into two compartments, each compartment being fitted
with two upright pipes, one (the inlet) dipping into the water in each
case, thus washing the gas which is then condensed by passing through
the upright pipes (the pipes of the various compartments are connected
by arch pipes). Each compartment is also furnished with a peculiarly
constructed overflow pipe, which is double inside each compartment, tho
two branches being united together in one pipe below the same, so that
whether the vessel is in a calm or a storm the water is preserved at a
uniform height at the dip pipe, the surplus water flowing away into the
bilges. The services or bye pass valves in connection with the washer
and condenser are so arranged that a supply of fresh clean water can be
placed in the hydraulic boxes at any time without stopping the manu-
facture of the gas.
The scrubber consists of a hydraulic box similar to the washers, one
compartment having a dip pipe and the other being surmounted by a
wrought-iron cylinder provided with the ordinary perforated sieve and
water spreader.
The gas holder consists of a holder and tank combined, the tank being
of iron and of a conical form so as to leave no waste space for gas, and
having also a flexible bag of india-rubber and canvas, of leather
coated with india-rubber or other suitable material secured to its
edge or lip, and an iron disc or crown on the top, so that the flexible
part will be free to descend completely inside the conical tank when
empty and of rising above the tank when full. The holder has an
iron cover secured to the upper edge of the tank and of sufficient
height to allow the flexible diaphragm to rise to its full height, and at
the same time preserve it from any external injury, and collects any gas
which may happen to escape, and conveys the same by a ventilator into
the open air. The flexible diaphragm is guided in its ascent and descent
by a brass tube secured to the centre of the iron disc, and which
traverses along a stationary guide rod fixed to the centre of the top of
the crown, and at the same time slides within a stationary tube of
wrought iron which is secured at the upper end to the centre of the
bottom of the tank and at the lower end to the framework of the ship.

page_text: If preferred the centre guide rod may be a tube and act as an escape
valve (to prevent the overcharging of the holder) by being carried
through the top of the cover into the ventilator.
The rising and falling of the flexible diaphragm is indicated to the
man in charge by a tell-tale consisting of a brass weight (connected to t
the iron disc by a length of gut passing over two pulleys and through a
brass bush in the cover) sliding inside an iron tubo so as not to be inter-
fered with by the motion of the vessel. An indicator is fixed to the
weight, and the same moves in a slot in the tube (which is fixed in the
retort space), so that the quantity of gas in the holder can be ascer- 1
tained in a moment by the man in charge, and the oil supply regulated
accordingly.
The holder is bye-passed, so that in case of accident or necessary
repair the gas may be made to pass direct from the scrubber to the regu-
lator (thence to the burners), and so cause no cessation in its manufacture
and supply. The iron framework of the holder and cover is so con-
structed (and with a manhole door in each) that the flexible diaphragm
may be removed and replaced by a new one (if necessary) without any
other part being interfered with.
The regulator is furnished with a flexible diaphragm attached to two
spiral springs, which are adjusted (so as to give the proper pressure) by
a hand screw and check nut on the top of the regulator. By this
arrangement the working of the regulator is not affected by the rolling
of the vessel, as would be the case with an ordinary regulator where the
pressure is regulated by weights.

page_text: year of our Lord One thousand eight hundred and seventy-two, in the
36th year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John Thomas Brown Porter, Her special
license that I, the said John Thomas Brown Porter, my executors, adminis-
trators, and assigns, or such others as I, the said John Thomas Brown
Porter, my executors, administrators, or 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 COMBINED GAS APPARATUS TO BE USED ON BOARD SHIP," upon
the condition (amongst others) that I, the said John Thomas Brown
Porter, my executors or administrators; by an instrument in writing
under my hand and seal, 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 John Thomas Brown Porter, do
> hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the accom-
panying Drawings and to the letters and figures marked theron, that is
to say :-
My said Invention relates to a peculiar combination and arrangement
of combined gas apparatus intended for use on board ship, and consists
in the combination as herein-after described of a number of vertical,
conical retorts, with a peculiar arrangement of combined washer, con-
denser, and scrubber, gas holder and gas regulator. The retorts may be
set singly or in pairs in circular ovens, so that one may be used in the
daytime and two or more at night, each pair of retorts being heated
from one furnace, the flues from which make a complete circuit round
the retorts by means of a spiral partition in the oven or otherwise, or
In the upper
each single retort may be heated by a furnace of its own.
end or other convenient part of these retorts is a disc made convex on
its upper face. This disc is intended to disperse the oil from which the
is manufactured over the inner sides of the retorts, and is fed with
oil and a small proportion of water or other liquid from cisterns supplied
gas

page_text: through funnels and syphon pipes fixed to the lids of the retorts, which
lids are fitted with any convenient fastening, such for example as hinged
bolts working in slots in the flanges of the lids, the said bolts carrying
nuts which on being slightly loosened are allowed to fall down and
release the lid when required for cleaning the retorts. The retorts are
widened at the top, that is to say, they are of a slightly conical form,
and are in some cases formed with a bulge round the internal side for
the oil to fall upon and for the flame to strike against on the outside, by
which arrangement however heavily the ship may roll or pitch the oil
flowing from the disc must of necessity fall upon a heated surface. The
disc may if desired have a large opening or short tube in its centre to
afford passage for the gas as it rises from the heated surface of the
retorts, but such opening is not absolutely necessary. An outlet pipe is
attached to the top of each retort for the escape of the gas, whilst the
bottom of the retort may be fitted with a cleaning cap.
The whole of the retort stack is enclosed in plates of cast iron ribbed
on the inside so as to leave an air space between the brickwork and the
plates which prevents the radiation of heat from the stack and thus
economises the fuel for the furnaces, and at the same time removes the
danger which might be caused to the vessel if the heat were not thus
confined, consequently the stack can be fixed in a much smaller space
than it otherwise could be. These plates are so arranged that any of
the retorts can be removed and a new one substituted without interfering
with the other parts of the stack, and so as to give easy access to any of
the flues or ovens for cleaning.
The improved combined washer and condenser consists of two
hydraulic boxes, each of which is divided into two compartments, each
compartment being fitted with two upright pipes, one (the inlet) dipping
into the water in each case, thus washing the gas which is then con-
densed by passing through the upright pipes, the pipes of the various
compartments being connected at the top by arch pipes. Each com-
partment is also furnished with a peculiarly constructed overflow pipo
which is double inside each compartment, the two branches being united
together in one pipe below the same, so that whether the vessel be in a
calm or a storm the water is preserved at a uniform height at the dip
pipe, the surplus water flowing away into the bilges. The services in
connection with the washer, condenser, and scrubber are so arranged that

page_text: a supply of fresh clean water can be introduced into the hydraulic boxes
at any time without stopping the manufacture of the gas.
The improved scrubber consists of a hydraulic box, similar to the
washers, one compartment having a dip pipe, and the other being sur-
mounted by a wrought-iron cylinder provided with the ordinary per-
forated sieve and water spreader.
The improved gasholder consists of a holder and tank combined, the
tank being of iron and of a conical form so as to leave no waste space
for
gas and having also a flexible bag of india-rubber and canvas, or of
leather coated with india-rubber or other suitable material secured to its
edge or lip, and an iron disc or crown on the top so that the flexible part
will be free to descend completely inside the conical tank when empty
and of rising above the tank when full. The holder has an iron cover
secured to the upper edge of the tank, and is of sufficient height to allow
the flexible diaphragm to rise to its full extent, and at the same time
preserve it from any external injury, whilst it also collects any gas which
may happen to escape, and conveys the same by a ventilator into the
open air. The flexible diaphragm is guided in its ascent and descent by
a brass tube secured to the centre of the iron disc, which tube traverscs
along a stationary guide rod fixed to the centre of the top of the crown
or cover of the holder, and at the same time slides within a stationary
tube of wrought iron secured at its upper end to the centre of the bottom
of the tank, and at its lower end to the framework of the ship. If
preferred the centre guide rod may consist of a tube and act as an
escape valve to prevent the overcharging of the holder by being carried
through the top of the cover into the ventilator:
The rising and falling of the flexible diaphragm is indicated to the
man in charge by a tell-tale, consisting of a brass weight connected to
the iron disc by a length of gut passing over guide pulleys, and through
an aperture in the cover, the said weight sliding inside an iron tube so
as not to be interfered with by the motion of the vessel. An indicator
is fixed to the weight, and the same moves in a slot in the tube, which is
fixed in the retort house, so that the quantity of gas in the holder can be
ascertained in a moment by the man in charge, and the oil supply
regulated accordingly.
The holder is bye passed, as is well understood, so that in case of
;

page_text: the scrubber to the regulator and thence to the burners, and so cause no
cessation in its manufacture and supply. The gasholder and cover are
both provided with man-hole doors, and the ironwork is so arranged
that the flexible diaphragm may be removed and replaced by a new one
(if necessary) without any other part being interfered with:
5
The improved regulator is furnished with a flexible diaphragm
attached to two spiral springs, which are adjusted so as to give the
proper pressure by a hand screw and check nut on the top of the
regulator. By this arrangement the working of the regulator is not
affected by the rolling of the vessel as would be the case with an ordinary 1
regulator, where the pressure is regulated by weights.
And in order that my said Invention may be fully understood I shall
now proceed moro particularly to describe the same, and for that purpose
shall refer to the several Figures on the annexed Sheets of Drawings, the
same letters of reference indicating corresponding parts in all the 1
corresponding Figures.
Figure 1 (Sheet 1) of my Drawings represents ä vertical section taken
through a pair of my improved gas retorts, and through the furnace for
heating the same; Figure 2 is a corresponding section; taken at right
angles to Figure 1, through one of the said retorts; and Figure 3 is a 2
horizontal section, the left-hand half of which is taken along the line 1, 2,
in Figure 1, and the right-hand half along the lino 3; 4; in the same
Figure, in order to show the formation and arrangement of the flues.
Figure 4 is a half front elevation and transverse vertical section of a
modified form of retort and setting, each retort being heated by a separate 2
furnace of its own; Figure 5 is a vertical section at right angles to
Figure 4, showing one of the said retorts with its furnace and fittings;
and Figure 6 is a half plan and horizontal section of a retort and setting
for the same, the section being taken along the line 5, 6, in Figure 5,
with the retort removed.
The retorts "A" are of cast iron, and are set either singly or in pairs in
circular ovens, so that any number can be used at one time according to
the number of lights requiring to be supplied.
3
The oil from which tho gas is manufactured is introduced into each
retort through a syphonic feed pipe B provided with a funnel; a similar 3
pipe "C" and funnel is fixed for the introduction of a small quantity of

page_text: water. These pipes B and O are each provided with a stop cock a and b,
and both pass through the lid of the retort and unite underneath (inside
the retort) in one vertical pipe D which is open at both ends, the upper
end standing a little above the junction to allow any gas to escape which
may pass up the pipe, and which would otherwise blow off at the syphons.
This arrangement insures a uniform and steady flow of the liquids, and
a corresponding constancy in the manufacture of the gas.
The introduction of water into the retorts along with the oil is to
prevent the formation of carbon in the retorts by carrying off the
decomposed vapours of the oil immediately after formation, as is well
understood.
After leaving the pipe "D" the oil and water fall upon a convex disc or
diaphragm “E,” and are thence dispersed over the hot sides of the retort
if the disc is fixed high up as in Figure 1, or if the disc be placed lower
in the retort, as in Figures 4 and 5, so as to become sufficiently heated
the oil is immediately volatilized without falling upon the retort; in
either case the oil will fall upon a heated surface however violent tho
motion of the ship may be.
The retorts may be made either as in Figures 1 and 4, or otherwise
modified to suit circumstances; in Figure 1 they are formed with a tail
piece or outlet with a cleaning cap F at its lower end, which being
removed allows the refuse to fall straight through; in Figure 4 the
retorts are shown much shorter and rounded off at the bottom, the
cleaning out of the same being effected from the top after removal of
the lid.
The retort lids are shewn as secured by means of hinged bolts, which
when loosened fall down and permit the lid to be removed, thereby
giving easy access to the inside of the retort for cleaning.
In case
The retorts are suspended from a flange round the top and secured in
their places by four lugs or ears d (Figure 6), with set screws.
of their requiring renewal either kind of retort can be lifted straight out
by means of a pair of blocks attached to the small travelling crane G,
shewn in Figures 4 and 5), and à new one substituted without
interfering with the brickwork or any other part of the stack and with-
out suspending the working of the other retorts by simply closing the
outlet valve H (Figure 5).

page_text: The oven or furnace in Figures 4 and 5 is provided with two dampers,
one e to the flue from the furnace (which also serves as a shield for the
bottom of the retort), and another to the outlet into the main fluc,
both dampers being regulated from the front of the stack, as shewn in
the Drawings. In the case of the longer retort (Figure 1) a spiral
partition is formed in the oven so as to carry the frame completely
round the retort before allowing it to escape into the main flue, and so
economise the heat.
The whole of the rotort stack is enclosed in plates of cast iron I
ribbed on the inside, so as to leave an air space between the brickwork K 1
and the plates, which prevents the radiation of heat from the stack, and
thus economises the fuel for the furnaces, and at the same time removes
the danger which might be caused to the vessel if the heat were not thus
confined, consequently the stack can be fixed in a much smaller space
than it otherwise could be. These plates are arranged so as to give easy 1
access to any of the flues or ovens for cleaning and are fitted with sight
holes and other adjuncts. The stack is provided with every accessory,
such as foot and hand rail, chains and pulleys, for dampers.
.
Each retort has an outlet L for the gas immediately under the lid with
a shut off valve or cock H leading into a main pipe M in front of the 2
stack, which conveys the gas direct by the ascension pipe N to the
washer and condenser herein-after described. The main pipe and shut-
off valves are of brass, the former is provided with cleaning caps h, and
at each end a small tube and cock is fixed to draw off
any sediment
which (when the ship has a list to either side) may accumulate. The 2
main as shewn in Figures 4 and 5 is placed higher than the retorts, so
that any imperfectly volatilized oil which may be carried into it with
the gas runs back into the latter and is volatilized afresh, thus
preventing waste.
The retort stack should be fixed athwartships and be placed in a 3
separato compartment cased with iron, and whenever it abuts upon a
bulkhead sufficient intervening space i is left, and air holes (Figure 4)
made in the plates which encase the brickwork to keep up a constant
current and so provide against all danger of fire. When the stack
adjoins the coal bunkers it is advisable to have a double bulkhead.
Figure 7 (Sheet 2) is a longitudinal vertical section of my improved
washer and condenser.
3

page_text: Figure 8 is a transverse vertical section of the same, and Figure 9 is a
plan with the upright pipes in section. This washer and condenser.
consist of a hydraulic box A divided into two compartments, each fitted
with two upright pipes B and C, the inlet pipe B dipping into the water
in each case, thus washing the gas which is then condensed by being
passed through the upright pipes C. The pipes B and C of the two
compartments are connected by arch pipes at D; each compartment is
furnished with a duplex overflow pipe a, a, consisting of two pipes
Icading into one, and placed fore and aft of the vessel so as to preserve
the water at one uniform level, whether in a calm or storm, the surplus
liquid flowing away into the bilges where a syphon is fixed to each
overflow pipe to prevent the gas from escaping. There is also a mud
hole door bin each compartment by which all the liquid can be run off,
and the washer thoroughly cleansed if required. A service pipe and
cock c is fixed to each compartment, the pipe dipping to nearly the
bottom of the box to form a seal so that a supply of clean water can bo
furnished at any time without stopping the manufacture of the gas.
0
Figure 10 is a longitudinal vertical section of my improved scrubber.
.
Figure 11 is a transverse vertical section of the same, and Figure 12
is a plan corresponding to Figure 10. This scrubber consists of a
hydraulic box A similar to the washer, one compartment having a dip
pipe B and duplex overflow a, the other having a single overflow pipe a'
and being surmounted by a wrought-iron cylinder O provided with a
perforated bottom or sieve d and a rose or water spreader e at the top,
the service pipe to the latter having a syphon to prevent the escape of
the gas through which either a constant or intermittent stream of water
may be supplied to the cylinder. There are two man-hole doors g, g, in
the cylinder to permit the same to be filled with coke or some other
suitable substance to assist in spreading the water and purifying tho
gas. The gas passes from one compartment of the hydraulic box to the
othier, through a hole in the partition at h. The outlet i of the scrubber
is at the top of the cylinder.
The connections of the washer, condenser, and scrubber are of wrought
iron, and are provided with brass three way valves, so that either of
them can be bye passed for cleaning without interfering with the working
of the other. Any number of washers and condensers or scrubbers
(more or less) may be used according to the size of apparatus required.

page_text: Figure 13 represents a vertical section of my improved gas holder,
which consists of a circular cover A and tank B combined, the tank (B)
being of iron, and containing a flexible diaphragm or bag C of leather
prepared with whitelead and tallow, or other suitable solution, and
coated on the outside with india-rubber or other suitable material.
This flexible diaphragm is secured at a to the edge or internal lip of the
tank, and is also secured to an iron disc or crown D on the top, so that
the flexible part is free to descend completely inside the tank when
empty, and of rising above the tank when full, as shewn on the Drawings
by dotted lines. The tank is made conical in order to leave no waste
space for gas which cannot be expelled, and to give sufficient play for the
iron crown in its ascent and descent, and is provided with a syphon and
cock E to draw off any liquid wbich may accumulate by condensation.
The iron cover A, which is secured to the upper edge of the tank B, is of
sufficient height to allow the flexible diaphragm C to rise to its full
extent, and to preserve it from any external injury. This cover or
holder is provided with a ventilator F, by which any gas which from
accident or other cause may escape from the holder is conveyed into the
open air, thus effectually preventing unpleasant odour and danger of
explosion.
The flexible diaphragm is guided in its ascent and descent by a brass
tube 6 secured to the centre of the iron disc or crown D, which traverses
along a stationary guide rod c fixed to the centre of the top of the cover,
and at the same time slides within a stationary tube of wrought iron d
provided with a brass bush at its upper end, which is secured to the
centre of the bottom of the tank B, the lower end being fastened to the
framework of the ship. The central guide rod c is screwed at the top
into an opening in the brass flange e, such opening being wider than
the diameter of the rod, so that the rod can easily be removed if
required.
By making the central guide rod c in the form of a tube instead
of a rod, and filling the outer tube d with water to form a scal
when the holder is empty or only partially filled, it may be made
to act as an escape valve to prevent the overcharging of the holder
by allowing the gas to be carried through the top of the cover into the
ventilator.
The rising and falling of the flexible diaphragm is indicated to the
man in charco by a tell-tale consisting of a hmse weight & sliding inside.

page_text: an iron tube H, so as not to be affected by the motion of the ship. The
weight is connected to the iron disc or crown D by a length of gut ƒ
passing through the brass flange of the guide rod on the top of the
cover, and over suitable guide pulleys. An indicator 9 is fixed to the
weight, and the same moves in a slot in the tube H (which is fixed in the
retort house), so that the quantity of gas in the holder can be ascertained
at any moment by the man in charge, and the supply of oil to the retorts
can be regulated accordingly.
The tank and cover have each a man-hole door h, h, and the iron..
framework of the whole is so constructed that the flexible diaphragm
may be removed and replaced, or renewed if necessary, without any other
part being interfered with.
The holder is bye passed, so that in case of accident or necessary
repair the gas may be made to pass direct from the scrubber to the
regulator (thence to the burners), and so cause no cessation in its manu-
facture and supply. The inlet and outlet of the holder (one of which
is shewn at I) may be placed in any convenient position, and the
shape or dimensions of the tank and cover can be modified to suit
circumstances.
Figure 14 is a vertical section of my improved regulator. This is
somewhat similar in its general construction to the holder, having a
circular case A of iron with a flexible diaphragm O furnished with a
guide rod a. The inlet pipe D is in the centre of the bottom; E is the
outlet pipe, and the flow of the gas is regulated by a conical valve b
attached to the guide rod a, which opens and shuts as the flexible
diaphragm rises and falls, so that an equal pressure is given, whether
few or many lights are burning. The pressure is regulated by two.
spiral springs c, c', one below the valve, and one above the diaphragm,
adjusted by means of a long hollow screw d, which serves as a guide.for
the upper end of the spindle a, and is provided with a check nut e to
prevent its being affected by the motion of the ship. The cover is pro-
vided with a ventilator f, which is carried into the one on the cover of
the holder. The regulator is bye passed in a similar manner to the
holder.
The whole of the apparatus is firmly secured to the ship so as not to
be displaced by the motion of the same, and all syphons are placed "fore
and aft," as the motion in that direction is much less violent than
athwart ships.

page_text: Having now described and particularly ascertained the nature of my
said Invention, and the manner in which the same is or may be used or
carried into effect, I would observe in conclusion that I lay no claim
generally to the use of conical upright gas retorts, with or without internal
spreading discs, for the manufacture of gas from oil; but what I con-
sider as novel and original, and therefore claim as the Invention secured
to me by the herein-before in part recited Letters Patent is,―
First. The construction and use for a ship's gas apparatus of conical
upright gas retorts provided with an internal bulge, substantially as and
for the purpose herein-before described.
Second. The application and use to and in the washers, condensers,
and scrubbers of a ship's gas apparatus of double overflow pipes, arranged
substantially as and for the purpose herein-before described.
Third. The construction and use of a gas holder for a ship's gas
apparatus having a conical tank combined with a closed cover, and with
a flexible diaphragm guided in its ascent and descent by a guide rod and
tubes, arranged substantially as herein-before described.
Fourth. The combination with the above-described gas holder of a
ventilator, pipe, and indicator, substantially as herein-before described.
Fifth. The peculiar construction of gas regulator for ship's gas
apparatus wherein the diaphragm is governed by spiral springs above
and below the same, substantially as herein-before described.
Sixth. The combination of the hercin-before described conical gas
retorts, washer, condenser, scrubber, gas holder, and gas regulator, the
whole forming a complete apparatus or plant for the manufacture of 5
illuminating gas on board ships, as herein-before described.
In witness whereof, I, the said John Thomas Brown Porter, have
to this my Specification set my hand and seal, this Nineteenth
day of March, One thousand eight hundred and seventy-three.
JOHN THOMAS BROWN PORTER. (L.S.)