IMPROVEMENTS IN THE MANUFACTURE OF GAS FOR ILLUMINATING AND OTHER PURPOSES, AND IN THE APPARATUS USED
Year: 1871

page_text: LETTERS PATENT to William Edward Newton, of the Office for
Patents, 66, Chancery Lane, in the County of Middlesex, Civil
Engineer, for the Invention of "IMPROVEMENTS IN THE MANUFACTURE
OF GAS FOR ILLUMINATING AND OTHER PURPOSES, AND IN THE APPARATUS USED
."-A communication from abroad by Darius Davison, of
the City and State of New York, United States of America.
THEREIN.
Scaled the 30th May 1871, and dated the 30th March 1871.
PROVISIONAL SPECIFICATION left by the said William Edward Newton
at the Office of the Commissioners of Patents, with his Petition,
on the 30th March 1871.
I, WILLIAM EDWARD NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Civil Engineer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN THE MANUFACTURE
OF GAS FOR ILLUMINATING AND OTHER PURPOSES, AND IN THE APPARATUS USED
THEREIN," to be as follows: —
This Invention mainly has reference to the production of gas by the
destructive distillation of coal, but is applicable in some of its features
to the manufacture of gas from other substances. It will suffice here,

page_text: nowever, to restrict the description to coal, and the leading object of the
Invention is to produce a larger quantity and better quality of gas from
a given quantity of coal than has heretofore been practicable, by
converting into gas a larger proportion of the vaporous matter which
usually escapes and settles in the form of coal tar or other residuum.
The Invention includes, firstly, a novel construction of the retort and
arrangement of its parts. The retort or vaporizing vessel consists of a
lower main retort and upper return one with the escape pipe for the
gas at the forward end of the latter, and whereby the mouth end of
the retort which contains the charge is largely protected from outside
exposure beyond the brickwork or setting of the retort, and a more
economical and perfect production of the gas is obtained. This part of
the Invention comprises the making of both the main and return retorts,
whether of clay or metal, in one piece, and a cap or bonnet formed of a
casting which is made to embrace both the mouth of the main retort
and (in a forwardly projecting or overhanging relation to the latter) the
front end of the return retort for the purpose of making the connection
of the pipe which carries off the gas with the forward end of the retort
generally, although not with that portion of it which contains the
charge. By thus setting the mouth of the main retort back, as it were,
the distance it is required to make the connection of the escape pipe
for the gas, and by making such connection with the return retort as
described, the mouth end of the retort containing the charge is less
exposed to the cooling effect of the atmosphere and mere vapor or
imperfectly formed gas rising from the distillation of the coal at the
mouth or charging end of the retort is prevented from passing off in a
direct manner to the stand pipe and is caused to travel the full length
of the main retort and return one, thereby converting the same into a
pure or useful quality of gas before leaving the retort.
Secondly. The Invention consists in returning at pleasure any coal
tar deposited in the hydraulic main of a gas apparatus back to any one
or more of the retorts in a bench or series of benches of retorts by means
of pipes, drip cups, and traps in separate connection with the retorts,
but in general connection with the hydraulic main, and so that the
return of coal tar to the retorts may be shut off at pleasure and the samo
be allowed to escape by the ordinary waste pipe or be returned to the
retorts for conversion into gas at certain periods after the charge in
them has been partly (preferably about ouc-half) distilled.

page_text: Thirdly. The Invention comprises a novel process of charging or
working the charge in a retort by dividing it up so that when a portion
of the charge has been partially distilled another or the remaining
portion is commencing to be distilled, whereby the thinner vapors and
gases which are emitted from the partially distilled portion, and which
move with a slower velocity, are made to commingle with the more
voluminous vapours emitted from the newly introduced portion of the
charge, moving at a higher velocity, and thus a more uniform supply
of gas is kept up and a more equal quality obtained by the mixing of
the different grades of gas emitted at different stages of distillation. To
this end the Invention includes a removable false bottom extending the
whole length of the retort, or nearly so, and divided longitudinally by a
vertical partition projecting up within the retort for about two-thirds of
its height, more or less. The half of the charge is put into the one half
of the retort thus divided longitudinally, and after the same has been
half distilled then the other half of the charge is introduced into tho
other half of the retort, and when half distilled the first half charge,
which by such time has been fully distilled, is drawn out and a fresh
half charge introduced in its place, and so on ad infinitum.
Another means for effecting the like end consists in depositing each
fresh supply of a divided ordinary charge in rear of the retort, and after
the same has been partially distilled drawing the same forwards to
occupy an advance position in the retort, and inserting a fresh supply
or portion of a divided charge in rear of it, thus keeping up a successivo
distribution of divided charges or rather portions of an ordinary charge
at intervals within the retort in a progressive manner from the rear
towards the mouth of the retort. A distinctive feature of this last
method of proceeding is the depositing of the partial charge in the first
place in the back part of the retort, thereby causing all its vapours to
travel throughout the length of the retort, which when an ordinary
retort is used largely prevents the voluminous vapour from passing off
in an unconverted state. This method of proceeding also includes
certain devices for facilitating its adoption. One of these devices is a
slide arranged for operation within the retort for the purpose of passing
the one charge or partial charge over and in rear of another. There is
likewise a charger composed of a sliding scraper and hod for charging
the retort.

page_text: Fourthly. The Invention consists in a combination of two retorts
arranged the one within the other, and the inner one, which contains
the coal to be distilled, being made with open ends, the front or charging
one of which ends is closed by a lid, while the other allows of the vapours
passing off in the rear to travel in a thin stream or strata between the
two retorts throughout their length to the stand pipe which carries off
the gas. This improvement, while applicable to new structures, may be
applied with advantage to retorts in present use without altering or
disturbing their connections, and protects them from injury either
by heat, the chilling contact of cold coal or vapours, and from that
destructive wear which takes place consequent on removal of the coke
or refuse, and by the free fit of the inner retort within the outer or
ordinary one, the former, which may be slid out or removed when
required, is prevented from straining by contraction or expansion of its
parts on the outer retort. Apart from these advantages, however, this
portion of the Invention effects a great economy and improvement in
the gas produced by causing a more uniform and thorough distribution
of the vapours over the heated surfaces of the retort for their conversion
into gas, and whereby there is a diminished or inferior residuum, the
vapours being more profitably utilized.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said William Edward Newton in the Great Seal Patent
Office on the 30th September 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
EDWARD NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of March, in the year
of our Lord One thousand eight hundred and seventy-one in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, a
give and grant unto me, the said William Edward Newton, Her special
Licence that I, the said William Edward Newton, my executors, adminis-
trators, and assigns, or such others as I, the said William Edward
Newton, my executors, administrators, and assigns, should at any time

page_text: 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 "Iм-
PROVEMENTS IN THE MANUFACTURE OF GAS FOR ILLUMINATING AND OTHER PURPOSES,
AND IN THE APPARATUS USED THEREIN," being a communication to me from
abroad by Darius Davison, of the City and State of New York, United
States of America, upon the condition (amongst others) that I, the said
William Edward Newton, my executors or administrators, by an instru-
Oment in writing under my, or their, or one of their hands and scals,
should particularly describe and ascertain the nature of the said In-
vention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office within six
calendar months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said William Edward Newton, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement, reference being had to the Drawing
hereunto annexed, and to the letters and figures marked thereon (that is
to say):
This Invention mainly has reference to the production of gas by the
destructive distillation of coal, but is applicable in some of its features
to the manufacture of gas from other substances. It will suffice here,
however, to restrict the description to the use of coal.
The leading object of the Invention is to produce a larger quantity
and better quality of gas from a given quantity of coal than has here-
tofore been practicable by converting into gas a larger proportion of the
vaporous matter which usually escapes and settles in the form of coal
tar or other residuum.
The Invention includes, firstly, a novel construction of the retort and
arrangement of its parts. The retort is formed with a lower main
retort and upper return one with the escape pipe for the gas at the
forward end of the latter, so that the mouth end of the retort which
contains the charge is largely protected from outside exposure beyond
the brickwork or setting of the retort, and a more economical and perfect
production of the gas is obtained. Both the main and return retorts
whether made of clay or metal are formed in one piece and is provided

page_text: with a cap or bonnet formed of a casting which is made to embrace
both the mouth of the main retort and (in a forwardly projecting or
overhanging relation to the latter) the front end of the return retort,
for the purpose, of making the connection of the pipe which carries off
the gas with the forward end of the retort generally although not with
that portion of it which contains the charge. By thus setting the
mouth of the main retort back, as it were, (the distance it is required
to make the connection of the escape pipe for the gas, and by making
such connection with the return retort as described,) the mouth end of
the retort containing the charge is less exposed to the cooling effect
of the atmosphere and more vapor or imperfectly formed gas rising
from the distillation of the coal at the mouth or charging end of the
retort is prevented from passing off in a direct manner to the stand
pipe, and is caused to travel the full length of the main retort and
return one, thereby converting the same into a pure or useful quality
of gas before leaving the retort.
Secondly. The Invention consists in returning at pleasure any coal
tar deposited in the hydraulic main of a gas apparatus back to any one
or more of the retorts in a bench or series of benches of retorts by means
of pipes, drip cups, and traps in separate connection with the retorts,
but in general connection with the hydraulic main so that the return
of coal tar to the retorts may be shut off at pleasure and be allowed to
escape by the ordinary waste pipe or be returned to the retorts for
conversion into gas at certain periods after the charge in them has been
partly (preferably about one half) distilled.
Thirdly. The Invention comprises a novel process of charging or
working the charge in a retort by dividing it up so that when a portion
of the charge has been partially distilled another or the remaining
portion is commencing to be distilled, whereby the thinner vapors and
gases which are emitted from the partially distilled portion and which
move with a slower velocity are made to commingle with the more
volumincus vapors emitted from the newly introduced portion of the
charge moving at a higher velocity, and thus a more uniform supply of
gas is kept up and a more equal quality obtained by the mixing of the
different qualities of gas emitted at different stages of distillation. To
this end the Invention includes a removable false bottom extending the
whole length of the retort, or nearly so, and divided longitudinally by a
vertical partition projecting up within the retort for about two-thirds

page_text: of its height more or less. The half of the charge is put into the one
half of the retort (thus divided longitudinally), and after the same has
been half distilled then the other half of the charge is introduced into
the other half of the retort, and when half distilled the first half charge
which by such time has been fully distilled is drawn out and a fresh half
charge introduced in its place, and so on ad infinitum.
Another means for effecting the like end consists in depositing each
fresh supply of a divided ordinary charge in rear of the retort, and after
the same has been partially distilled drawing it forwards to occupy an
advanced position in the retort and inserting a fresh supply or portion
of a divided charge in rear of it, thus keeping up a successive dis-
tribution of divided charges or rather portions of an ordinary charge at
intervals within the retort in a progressive manner from the rear towards
the mouth of the retort. A distinctive feature of this last method of
proceeding is the depositing of the partial charge in the first place in
the back part of the retort, thereby causing all its vapors to travel
throughout the length of the retort, which when an ordinary retort is
used largely prevents the voluminous vapor from passing off in an
unconverted state. This method of proceeding also includes certain
devices for facilitating its adoption. One of these devices is a slide
arranged for operation within the retort for the purpose of passing the
one charge or partial charge over and in rear.of another. Thero is
likewise a charger composed of a sliding scraper and hod for charging
the retort.
Fourthly. The Invention consists in a combination of two retorts
arranged the one within the other, the inner one (which contains the
coal to be distilled) being made with open ends, the front or charging
one of which ends is closed by a lid, while the other allows of the vapors
passing off in the rear to travel in a thin stream between the two retorts
throughout their length to the stand pipe which carries off the gas.
This improvement while applicable to new structures may be applied
with advantage to retorts in present use without altering or disturbing
their connections. It also protects them from injury either by heat or
the chilling contact of cold coal or vapors, and from that destructive
wear which takes place consequent on removal of the coke or refuse,
and by the free fit of the inner retort within the outer or ordinary one,
the former, which may be slidden out or removed when required, is
prevented from straining by contraction or expansion of its parts on the

page_text: outer retort. Apart from these advantages however this portion of the
Invention effects a great economy and improvement in the gas produced
by causing a more uniform and thorough distribution of the vapors
over the heated surfaces of the retort for their conversion into gas,
whereby there is a diminished residuum, the vapors being more
profitably utilized.
In the accompanying Drawing Fig. 1 represents a front elevation of
a bench of retorts with attachments in illustration of the first and
second parts of the Invention, the distinguishing features of which may
either be used separately or collectively, and which may have combined
with them if desired the other features of the Invention, or certain of
them.
Fig. 2 is a longitudinal section of one of the retorts constructed in
accordance with the first part of the Invention; Fig. 3 is a transverse
section of the same; Fig. 4 is a front view thereof with the metallic
mouthpiece, cap, or bonnet removed; and Fig. 5 is a similar view with
the cap applied to it,
Figures 6 and 7 represent longitudinal and transverse sections of a
retort in illustration of the third part of the Invention as exemplified
by one modification.
Fig. 8 is a longitudinal section of a retort in further illustration of
the third part of the Invention showing a different modification and
combination of devices; and Figures 9 and 10 are plan and side views
of the implement and slide used in charging the retort according to this
last-mentioned modification.
Fig. 11 is a side elevation of a gas retort constructed in accordance
with the fourth part of the Invention, and which may also combine the
feature of the third part of the Invention, as shown in Figures 6 and 7.
Fig. 12 is a transverse section of the retort in illustration of the
fourth part of the Invention with the modification shown in Figures 6
and 7 applied to it; and Fig. 13 is a longitudinal section of the same,
but not having the feature exhibited in Figures 6 and 7 combined
with it.
Referring in the first instance to Figures 1, 2, 3, 4, and 5, A repre-
sents the front of the brickwork or setting of a bench of five retorts,
which may be made of either clay or metal, but preferably clay. Each
of the retorts is subdivided into or composed of a lower main retort B

page_text: (in which the charge is placed), and an upper return retort C preferably
of cylindrical construction and connected with the main retort in its
rear, as at b, Fig. 2. This return retort is heated in common with the
main retort, and serves to conduct the gas as made to the escape or stand
pipe D placed beyond the front end of the lower retort, and as regards
the outside exposure of which it is immaterial inasmuch as all available
vapor has been converted into gas before reaching it. But it is impor-
tant that the charging end of the lower retort should project as little as
possible beyond the setting, as such would expose a portion of the charge
to the cooling effect of the outside atmosphere. This is attained by
connecting the stand pipe D with the return retort in front, and all
vapor rising from the coal at the mouth end of the main retort B
instead of being passed off and crowded up the stand pipe by the gas
produced at the rear of the retort is compelled to travel the full length
of the lower retort and back along the upper retort before it passes off to
the stand pipe. This ensures a more thorough conversion of the vapor
into gas, and a more perfect and economical production generally of the
gas before it escapes by the stand pipe D. The mouth ends of both
retorts B, C, are fitted with a metallic mouthpiece, cap, or bonnet E
formed of a single casting and bolted to the mouth ends of the retorts
and resting upon the upper mouth, as seen in Fig. 2, to relieve the
bolts of strain. This cap is made with two mouths or branches arranged
to face the mouths of the retorts, and provided with lids for charging,
discharging, and cleansing purposes, and the upper one of the two is
made to extend beyond the lower one for attachment of the stand pipe
to it, as at c. Fis the usual hydraulic main continued from bench to
bench of the gas producing apparatus, and G is the waste pipe by which
the coal tar deposited in the main is carried off. To make available this
residuum, or a portion of it for conversion into gas, a pipe II fitted with
a cock e is connected with the waste pipe G between the connection of
the latter with the main. A shoulder f serves to retain a certain
amount of coal tar in the main, but admits of an excess running off by
the waste pipe G. Connected with the pipe I, beyond the cock e,
relatively to the attachment of the pipe with the main (as by a branch g
and lower horizontal pipe ) are a series of divided distributing or drip
pipes k, each provided with a cock, drip cup, and trap, and connected
with the several retorts respectively in proximity to their charging ends,
and preferably over removable concave inclined plates or surfaces (not
shown in the Drawing), and which serve to conduct coal tar as supplied

page_text: by the pipes some little distance into the retort, to prevent collection
at the mouth of the latter, and facilitate the evaporation thereof in
contact with the hot bottom of the retort. By these appliances, which
are irrespective of any particular construction of the retorts, coal tar
collected in the main F may (by opening the cock e, the cock g, and the
cocks in the distributing or drip pipes,) be admitted at pleasure and
in any desired quantity into the retorts for conversion into gas during
the whole time of the distillation of each charge, or during any portion
of such tinic, and thus a comparatively useless product is made available
to the more economical production of the gas, and in a manner that
admits of all desirable control. The return of coal tar from the main is
only desirable after the charge in the retort has been partially (say about
one-half) distilled, and the amount so returned may be varied to suit
circumstances, and in some cases may be prevented from returning
altogether, all of which conditions and requirements the system of
connections here shewn and described for utilizing the coal tar in the
main provides for.
The third general division of the Invention will be understood by
reference to Figures S, 9, and 10. In the process heretofore adopted of
charging and working the charge in a retort the entire charge is about
two hundred pounds of coal. The coal is ordinarily put into the retort
at one and the same time, and spread over nearly the entire bottom of
the retort throughout its length, where it is allowed to remain for a
given time, which may be assumed to be four hours, till, in fact, the
gas is exhausted from the charge. This mode of operation causes a
large volume of vapor to be disengaged when the charge is introduced,
and a gradually diminishing volume afterwards till the operation is
completed, so that the flow of gas from the retort is unequal through-
out the distillation of the charge, the gas and vapor passing rapidly from
the retort at first, and gradually diminishing in velocity and volume to
the end. This causes an unequal action on the gas and vapor in contact
with the heated surfaces of the retort. Much of the vapor distilled from
the coal at and near the mouth of the retort passes from the retort
unconverted into gas, and the gas produced from the coal during the
latter part of the process of distillation passes so slowly from the retort
(by reason of its reduced volume), that a considerable portion of the gas
is burned in the retort and converted into fixed carbon or lampblack,
thereby further reducing the volume and illuminating quality of the gas
produced. To obviate these defects instead of placing the entire charge

page_text: at one feed along the bottom of the retort it is divided into two equal
parts, and cach part is introduced into the retort at about equal intervals
of time. For instance, if the charge of two hundred pounds is divided into
two equal parts, the one of such divisions or halves would be charred in
the back end of the retort (when the latter is of ordinary construction),
and allowed to distil about two hours (more or less), after which the
retort is opened and such partially distilled half charge hauled forward
on the bottom of the retort and the remaining half charge introduced
over it to the rear of the retort. This method of charging is represented
in Fig. 8 of the Drawing. The two half charges are then allowed to
distil for about two hours, making four hours in all, or thereabouts, for
the first half charge, which then (having the gas and vapor all distilled
from it) is drawn from the retort, and the remaining half charge at the
back end of the retort is hauled forwards and a fresh half charge intro-
duced over it in the rear, and a repetition of the process just. described
is continued. By this improved process the reduced quantity of fresh
coal introduced into the retort at one time yields a less voluminous
amount of vapor, and consequently such vapor passes more slowly out
of the retort and prolongs its exposure to the hot surfaces of the latter;
likewise the rich gas and vapor from the fresh coal has to pass over the
licated and partly distilled pile of coal in front of it, and is consequently
combined with the poorer gas that is being climinated from the partly
distilled portion drawn towards the mouth of the retort. Furthermore,
dividing the entire charge and introducing the divided portions at
successive intervals, as described, effects a nearly uniform distillation in
volume of vapor and gas, and consequently a more nearly uniform flow
of gas in volume continually from the retort, thus obtaining a nearly
uniform action of the heat, both as regards time and space, and a
thorough mixing of all the products of distillation, together with a very
thorough conversion of all the vapors from the coal into permanent rich
illuminating gas.
To facilitate the placing of the partial charge at the extreme back end
of the retort a charger such as that shown at Figures S, 9, and 10 may be
used. This charger consists of a sliding scraper J and hod K within
which latter the scraper is arranged, the hod having a rear extension pro-
vided with a handle for pushing in or drawing out the whole implement.
The scraper J is operated by a rod or handle m, running sufficiently back-
wards to allow of the scraper's operation from a position in front of the

page_text: retort after the implement has been introduced its full length therein. To
discharge the coal the scraper J is held stationary while the hod Kis
drawn outwards, or the scraper may be pushed inwards simultaneously
with the drawing outwards of the hod. When it is required to deposit
a charge over a previous charge lying in the retort, as shewn in Fig. 8,
a stationary incline or slide L of a length to suit and provided with a
stop n at its back that strikes against the front of the retort to gauge
the position of the slide in the latter may be used. This slide, which
is entered within the retort at each opening thereof and withdrawn at
cach closing of the same, is projected into the retort till its front end
rests on or overhangs a pile or half charge drawn from the rear of the
retort to make room for a fresh charge. The slide may be made
arched in its transverse section to guide and steady the charger when
introduced along and over it. The above described charging implement
and the process of manufacturing coal gas by dividing the charge is
designed to be applied to retorts at present in use in gas works as well
as to new retorts without any material change in the present mode of
constructing retorts, and without any change in the various apparatus
and processes connected with the manufacture of illuminating gas after
the same passes from the retort or retorts.
Figures 6 and 7 of the Drawing show a modification also applicable
to retorts of various kinds for effecting the same object. Instead of
feeding in each fresh half charge successively in rear of a partially
distilled pile, each half charge is arranged side by side throughout the
whole length of the retort or thereabouts, but the same method of
working prevails as in the previous arrangement, the one half charge
being half distilled or thereabouts before a fresh half charge is introduced
by the side of the partially distilled charge in the space left by a
removed fully worked half charge, and so on successively, whereby the
same general advantages are obtained as described with reference to
Figures 8, 9, and 10. To carry into effect this change in the disposition
of the half charges within the retort a false bottom M (Figures 6 and 7),
having a longitudinal partition o arranged to project upwardly from it
for about two-thirds of the height of the retort or otherwise, establishes
a communication from its opposite sides along the top of the retort.
This false bottom is slidden in over the bottom of the retort and the
half charges are introduced at intervals along cither side of the par-
This false bottom also serves to protect the bottom of the
tition o.

page_text: retort from injury and fouling, and may readily be removed when
necessary to cleanse it.
The fourth part of the Invention is shown at Figures 11, 12, and 13.
It consists in a combination of two retorts, the one arranged within the
other. The inner one (which contains the coal to be distilled) is made
with open ends, the front or charging one of which is closed by a lid
while the other allows of the vapors passing off in the rear in a thin
stream between the two retorts throughout their length to the stand
pipe which carries off the gas.
This improvement while applicable to new structures may be applied
with advantage to retorts in present use without alteration of them or
disturbance of their connections, and it protects them from injury either
by heat or the chilling contact of cold coal or vapor, and [from that
destructive wear which takes place upon the removal of the coke or
refuse. By the free fit of the inner retort within the outer or ordinary
one (the former which may be slid out or removed when required) is
prevented from straining by contraction or expansion of its parts on the
outer retort.
Apart from these advantages, however, this improvement effects a
great economy in the production of the gas and improves its quality by
causing a more uniform and thorough distillation of the vapors over the
heated surfaces of the retort for their conversion into gas, thereby
reducing the quantity of coal tar deposited from the vapors which are
accordingly more profitably utilized.
Figures 11, 12, and 13, N represents a gas retort of ordinary con-
struction, but provided with a lid at its mouth secured by the usual
fastenings, and with a gas escape or stand pipe in front. Within this
retort N is another and smaller retort P of nearly the same length
as the outer retort, on the bottom of which it rests so as to be capable
of being slidden out or removed when required without disturbing
the connections of the outer retort. This inner retort P (which may
bo of metal or other suitable material) is made to fit loosely in the
outside retort so as not to strain by expansion or contraction upon the
latter, and is of such dimensions in its transverse section as to leave
a thin intervening space u around and between it and the outer retort
throughout the length of the retorts. The inner retort P is furthermore
constructed open at its ends, the front opening or mouth of it being
fitted with a lid w, which may be closed and luted after such retort has

page_text: been charged with the coal to be distilled. The rear opening serves
for the vapors as generated to pass off to and along the space a, which
spreads them and brings all the vapors uniformly in contact with the
heated surfaces of the retort, thus producing a more perfect and
thorough conversion of the vapors into gas by the time the same arrive
at the stand pipe 8, thereby producing a larger quantity and better
quality of gas from a given amount of coal.
The lid at the front end of the inner retort may be variously
constructed, but it is desirable to make the same capable of ready
adjustment to and from its place, to facilitate which it is provided with
a triangular handle y, arranged to take its bearing upon or within
the outer retort, and serving to brace and hold up the lid when in
its place, and is within easy reach on removing the lid from the outer
retort.
The inner retort P may, if desired, be fitted with a longitudinal
vertical partition, as shown in Fig. 12 to work the charge in a divided
manner, as described, with reference to Figures 6 and 7, or it may be
constructed without such partition for working the entire charge in the
manner shown at Fig. S, or at one and the same time in the ordinary
manner.
Having now described the Invention which has been communicated
to me by my foreign correspondent, and having explained the manner
of carrying the same into effect, I claim as the Invention secured to
me by Letters Patent as aforesaid,—
First. The combination with the main retort B in which the charge
is placed of the upper return retort C, arranged to communicate with
the main retort at or near its rear end and connected with the escape or
stand pipe in front of said main retort, as and for the purpose herein set
forth.
Second. The use of the metallic mouthpiece, cap, or bonnet E
constructed with an upper forward extension for attachment of the
stand pipe, and provided with lids in front in combination with the lower
main retort B and upper return retort C, made to communicate in their
rear, as herein set forth.
Third. The combination with the hydraulic main of the gas apparatus
and a bench or series of benches of retorts of a system of pipes provided
with cocks, drip cups, and traps for controlling at pleasure the return
of coal tar from the main to the retorts, or of allowing it to escape

page_text: by the waste pipe as may be desired, as and for the purpose herein set
forth.
Fourth. The process herein described of manufacturing coal gas by
depositing each fresh supply of a divided entire charge of coal suc-
cessively within the retort during the distillation of a previous divided
portion of the charge, as set forth.
Fifth. The false bottom M provided with a longitudinal dividing plate
or partition o, as described.
Sixth. Manufacturing coal gas by depositing cach fresh supply of a
divided entire charge at the rear of the retort, and successively dis-
tributing such portions or divisions of the charge at intervals within the
retort in a progressive manner from the rear towards the mouth of thio
retort, as described.
Seventh. The use of the slide L within the retort to facilitate the
passing of one divided portion of the charge over and in rear of another
portion thereof.
Eighth. The charger shewn at Figures 8, 9, and 10, and composed of
a sliding scraper J and hod K arranged for operation in relation with
each other and with the retort, as shown and described.
Ninth. The use of an inner retort P capable of being slidden out or
removed from the outer retort N, as and for the purpose described.
Tenth. The combination and arrangement of the outer retort N and
inner retort P (provided with lids at their approximate ends) having au
interposed space u between them in communication at reverse ends of
the combined retort with the opening and stand pipe or outlet 8,
whereby an uniform distribution and perfect circulation of the vapors
and gases is established in intimate connection or contact with the hot
surfaces of the retorts, as described.
In witness whereof, I, the said William Edward Newton, have
hereunto set my hand and seal, the Thirtieth day of September,
in the year of our Lord One thousand eight hundred and seventy-