IMPROVEMENTS IN SUMPTION OF FUEL IN SUPERHEATING STEAM, AND IN THE APPARATUS EMPLOYED -THEREFOR
Year: 1860

page_text: LETTERS PATENT to Nicholas Wehnert, of 3, King Street, Cheapside,. in
Cox-
the City of London, for the Invention of "IMPROVEMENTS IN
SUMPTION OF FUEL IN SUPERHEATING STEAM, AND IN THE APPARATUS EMPLOYED
-THEREFOR." A communication from abroad by Paul Trochon, of. 20,
Rus Ruffaut Paris
Sealel the 7th Febriary 1861, and dated the 14th August 1860.
PROVISIONAL SPECIFICATION left by the said Nicholas Wehnert at the
. Office of the Commissioners of Patents, with his Petition, on the
14th August. 1860..
J..NICHOLAS WEHNERT..of 3, King Street. Cheapside, in the City of London,
do hereby declare the nature of the Invention for "IMPROVEMENTS IN THE
CONSUMPTION OF FUEL IN SUPERHEATING STEAM, AND IN THE APPARATUS EMPLOYED
THEREFOR" to be as follows:-
.My. Invention. consists in effecting separately the combustion of the gases
as well as the fixed carbon, .coke, or charcoal into which all species of fuel
resolve themselves when burnt, and which, technically speaking, afford two
separate and distinct sources of caloric. I subject, therefore, coals, lignites,
peat, or wood, to destructive distillation, in a form of apparatus which enables
me, first, separately. to consume the gases as well as the coke of the particular
kind of combustible operated on; secondly, to obtain a more near approximation
Price Sd.1

page_text: of the practical to the theoretic heating or calorific power of each kind of fuel
than has ever yet been obtained in practice; and, lastly, to most economically
generate and subsequently superheat steam.
The apparatus consists essentially of an ordinary cylindrical, or it may other
form of boiler, within which, in the part usually occupied by the grate or
furnace, a gas retort or retorts is or are arranged, either horizontally or
vertically, and heated by flues leading from a furnace or grate of ordinary
construction also within the boiler. The gas from the retort or retorts
proceeds into a cylinder or cylinders, called by me "generators," through a
triple or compound tube, which, on the principle of the Argand lamp, admit's
air externally as well as internally to the flame when the gas is burnt in the
cylinder or generator. The arrangement of tubes is furnished with stop cocks,
by which both the flow of gas as well as the quantity of air admitted to the
flame can be adjusted, and hence complete combustion, as in a lamp. is
arrived at without any production of smoke. The gas or flame proceeding
from the combustion of the fuel on the fire-bars, or, in other words, from the
furnace used to heat the retorts, is admitted near to the mouth of the Argand
tube, but a little in advanve of it into the generators in which the gas from
the retorts is burnt, and which, on putting the apparatus to work, it serves in
the first instance to inflame. The united products of combustion and flame
which exist in the generators are led through a system of flues arranged
within the boiler, and so disposed that the water may be most effectively
heated; finally, the gases escape into the smoke box beneath the chimney,
and then serve to superheat the steam by parting with their remaining heat to
a serpentine arrangement of pipe, through which the steam passes from the
steam chamber to the steam or eduction pipe, and which serpentine arrange
ment is placed in the smoke box. The generators, as well as the flues, arc
so arranged that they shall be wholly surrounded with water, in order that
there may be no heat lost as regards the vaporisation. The coke or solid
carbonaceous matter which remains in the retorts after the distillation of the
gas is raked out, and by means of a moveable plate attached to the front of the
furnace, made to descend on to the furnace bars, where, by its combustion, it
serves to eliminate the gas from a fresh portion of fuel when the retort is
recharged. The furnace is provided with perforated doors and an ash-pit, the
latter being separated from the bottom of the boiler by a stratum of water,
which serves to receive the heat radiated and emitted by the glowing cinders
which fall from the bars. In order that the flow of gas from the retorts may
continue uninterruptedly whilst the boiler is in use, I prefer a double retort,
the separate compartments of which I charge alternately, the grate burning off

page_text: also alternately their united produce of coke.
The size of the fuel introduced
into the retort is immaterial, and I employ with great economy the clean dust
from coal. The size of the fire-bars, however, I adjust to suit the nature of
the coke or fixed carbon coming from the retorts.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Nicholas Wehnert in the Great Seal Patent Office on the
14th February 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, NICHOLAS
WEHNERT, of 3, King Street, Cheapside, in the City of London, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of August, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-fourth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Nicholas Wehnert, Her special licence that I, the said Nicholas Wehnert, my
executors, administrators, and assigns, or such others as 1, the said Nicholas
Wehnert, my executors, administrators, and assigns, should at any time agree
with, and no others, from time to time and at all times thereafter during the
term therein expressed should and lawfully might make, use, exercise, and
vend, within the United Kingdom of Great Britain and Ireland, the Channel
Islands, and Isle of Man, an Invention for "IMPROVEMENTS. IN
CON-
SUMPTION OF FUEL IN SUPERHEATING STEAM; AND IN THE APPARATUS EMPLOYED
THEREFOR," a communication to me from abroad by Paul Trochon, of 20,
Rue Buffant, Paris, upon the condition (amongst others) that 1, the said
Nicholas Wehnert, my executors, or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly describe
and ascertain the nature of the said Juvention, and in what manner the same
was to be performed, and cause the same to be filed in the Great Seal Patent
Oflice within six calendar months next and immediately after the date of the
said Letters Patent.
THE
NOW KNOW YE, that I, the said Nicholas Wehnert, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:-
My Invention consists in effecting separately the combustion of the gases as
well as the fixed carbon, coke, or charcoal into which all species of fuel resolve

page_text: themselves when burnt, and which, technically speaking, afford two separate
and distinct sources of caloric. I subject, therefore, coals, lignites, peat, or
wood to destructive distillation, in a form of apparatus which enables me, first,.
separately to consume the gases, as well as the coke of the particular kind of
combustible operated on; secondly, to obtain a more near approximation of
the practical to the theoretic heating, or calorific power of each kind of fuel.
than has ever yet been obtained in practice; and, lastly, to most economically
generate and subsequently superheat steam.
"
The apparatus consists, essentially, of an ordinary cylindrical, or it may be
other form of boiler, within which, in the part usually occupied by the grate
or furnace, a gas retort or retorts is or are arranged, cither horizontally or
vertically, and heated by flues leading from a furnace or grate of ordinary
construction also within the boiler. The gas from the retort or retorts
proceeds into a cylinder or cylinders, called by me generators," through a
triple or compound tube, which, on the principle of the Argand lamp, admits
air externally as well as internally to the flame when the gas is burnt in the
cylinder or generator. The arrangement of tubes is furnished. with stop cocks,
by which both the flow of gas as well as the quantity of air admitted to the
flame can be adjusted, and hence complete combustion, as in a lamp, is
arrived at without any production of smoke. The gas or flame proceeding
from the combustion of the fuel on the fire-bars, or in other words, from the
furnace used to heat the retorts, is admitted near to the mouth of the Argand
tube, but a little in advance of it, into the generators in which the gas from
-the retorts is burnt, and which, on putting the apparatus to work, it serves in
the first instance to inflame. The united products of combustion and flame
which exist in the generators are led through a system of flues arranged
within the boiler, and so disposed that the water may be most effectively
heated; finally, the gases escape into the smoke box beneath the chimney, and
there serve to superheat the steam by parting with their remaining heat to a
serpentine arrangement of pipe, through which the steam passes from the
steam chamber to the steam or eduction pipe, and which serpentine arrange-
ment is placed in the smoke box. The generators as well as the flues are so
arranged that they shall be wholly surrounded with water, in order that there
may be no heat lost as regards the vaporisation. The coke or solid carbona-
ceous matter which remains in the retorts after the distillation of the gas is
raked out, and by means of a moveable, plate attached to the front of the
furnace, made to descend on to the furnace bars, where, by its combustion, it
serves to eliminate the gas from a fresh portion of fuel, when the retort is
recharged. The furnace is provided with perforated doors and an ash-pit, the

page_text: latter being separated from the bottom of the boiler by a stratum of water,
which serves to receive the heat radiated and emitted by the glowing cinders
which fall from the bars. In order that the flow of gas from the retorts may
continue uninterruptedly whilst the boiler is in use, I prefer a double retort,
the separate compartments of which I charge alternately, the grate burning off
also alternately their united produce of coke. The size of the fuel introduced
into the retorts is immaterial, and I employ with great economy the clean dust
from coal. The size of the fire-bars, however, I adjust to suit the nature of
the coke or fixed carbon coming from the retorts.
And in order that the said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawings hereunto
annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a longitudinal section of a stationary boiler, constructed accord-
ing to this Invention. A, an ordinary D-shaped gas retort, flat bottomed and
rounded at the back end; it is divided in the middle vertically, and so forms,
in fact, two retorts. On the back a diaphragm is also cast, and is shown in
the Drawing by a, a', a Both compartments of the retort are closed by
stopper plates or lids I, which extend over the edges of the retort mouths, and
are kept in their place by means of a lever bar or bars J' moving on an axis
1, which is bolted into the upper part of the retort in a line with the diaphragm
and a screw J, furnished with a handle J". A lute of clay or other suitable
material is also employed to increase the closeness of the adhesion of the lids to
the retort face. A cup-shaped depression in each lid serves to steady the points of
the screws. Staples screwed into the lids enable their removal or attachment.
H is the escape pipe for the gas; B, B', B", B, B, represent the cornices
and brackets which extend horizontally within the internal cylinder T, T, T",
T, and serve to support the retort as well as to form the "sole" of the hearth
flues C; C is the hearth fuc which occupies the space between the upper part
of the cylinder T, T', T", T, and the upper surface of the retort A. The flue
is double in consequence of the diaphragm a, a, a, so that the gases proceed-
ing from the fire hearth follow two channels, escaping separately by the
"hearth escape flues" C; D shows the fire hearth, fire bars, &c.; d is the
"dead plate" in front of the bars, and before which are the fire doors G open-
ing, as shown in the Drawing; E is a horizontal plate lying immediately before
the mouths of the retort, and longitudinally divided into two parts, each of
which is hinged to the front of the boiler, and hence is capable of being
deflected towards the "dead plate;" I term these plates the "coke deflectors,"

page_text: and they serve to deflect the coke as it is raked from the retort mouths on to
the hearth and fire bars. They also serve to increase at will the aeration of
the coke on the fire-bars independently of or in conjunction with the fire-door
and ash-pit. Fis the ash-pit, which is provided with a perforated door, in all
respects similar to that next to be described for the fire-door" G. The fire-
door is perforated with a series of holes for the admission of air to the hearth,
and is capable of being left open or closed at option by means of a sliding
plate. H is the escape pipe for the gas generated in the retort, and is described
in connection with the retort A. 1, 1, J, J, are the lids and their modes of
attachment, already described in connection with the retort; K is an ordinary
stop-cock, regulating the flow of the gas from the retort into the "argand
burner;" L, L', are concentric pipes, which, with the terminal part of the gas
pipe H, form the arrangement for effecting the combustion of the gaseous pro-
ducts resulting from the distilled portions of the fuel, and which, from the
similarity of its principle to that of the lamp termed the argand, I have termed
the "argand burner." These pipes L, L, are furnished with funnel-shaped
-mouths, arranged concentrically, and immediately behind the larger or exte-
rior funnel and intermediate between that funnel and the elbow pipe of the
gas pipe H. a stop-cock, similar to that placed on the gas pipe H, is
arranged in a manner so that it shall act only on the inner air pipe, closing or
opening it independently of the exterior air pipe, which is left free. I do not
describe the arrangement of this stop-cock, because it possesses no novelties of
construction. Care, however, is to be taken that such part of it as intersects
the outer air pipe shall not interfere with the current in that, pipe.
Lion occupied by the air cock is not shown in the Drawing, to avoid complication,
but will be sufficiently clear from the above description. The position of the gas
pipe H is intermediate and concentric with the air pipes, and by this general
arrangement a current of air is admitted both on the outer as well as to the
inner side of the flame, which is composed of a series of jets formed by the
mouth of the gas pipe, which, as will be seen by the Drawing, is of an annular
form, being closed by a perforated ring as in the so-called argand gas burners.
The value of the arrangement of being able to more or less stop the interior
pipe at option is, that by doing so, the flame may be much elongated, since it
will extend further into the burner flue to obtain the extra amount of oxygen
necessary for its combustion. By the use of the double regulation of the gas
and air a complete combustion of the gases and consequently the maximum
amount of heat which such combustion is capable of producing, may be obtained.
I term the air pipes aerators. M is the burner flue, which is double, that is
to say, 'exists' on either side of the boiler. I call it so because the combustion
The posi-

page_text: of the gas from the retort takes place in it. It also serves for the conduit of
the flame or gases proceeding from the hearth, and which gases serve to ignite
the gas proceeding from the gas pipe H. N is the fire-hox, into which pass
out of the burner flues the united products of combustion from the burning of
the gases from the retort, and the ignition of the coke on the hearth.
With regard to the burner flues I by no means restrict them to enter or
pass at once into the fire box, since in high boilers. such as used for marine
purposes. they may be connected with other pipes or fines, or even a series of
tubes for the purpose of obtaining increased heating surfaces. such pipes or
tubes, however, always terminating, in the "fire box," as aforesaid, for the
"burner flues" in the arrangement described. Since these products of com-
bustion retain a very clevated temperature I employ them finally in the fire
box to heat a flattened helix or coil of iron or copper pipes, which I term the
superheating coil. aud through which the steam from the steam box.or steam
dome Q passes out of the boiler by means of the pipe P₁ placed in the
chimney flue O. The form which may be given to the fire box may be various.
but from the advantages which it offers for resisting pressure I prefer the form
represented in the elevation Drawing. Figure 3. O. The chimney flue passes
directly into the chimney or delivers the products of combustion into ordinary
side flues, where the boiler is of very large size, and there may exist a high
chimney ordinarily speaking, however, high chimnies are not required to
maintain the draft in the boilers. P is the steam eduction pipe terminating at
its upper extremity in a funnel mouth within the dome Q and connected
below by a collar with the superheating coil situated within the fire box N;
P is the exit pipe for the steam, and passes through the chimney flue and
chimney to the outside of the boiler; Q is the steam box or dome, and is of
ordinary construction: R is the man-hole. also of ordinary construction;
S, S¹, SS, represent the outlines of the external shell of the boiler or
water space; and T, T. T". T", the internal cylinder, which from its con-
taining the coke, hearth, retort, &c., I term the "generator" or "heat gene-
rator; "Z, Z, shows the water line, and x, x¹, x, x, x, are the various
brackets and supports employed to maintain the various parts of the apparatus
n their place.
Figure 2 represents the fire box in sectional elevation; M, M, burner flues;
N, the exterior of the box; Y, the superheating coil, consisting of a flattened
r square helix or coil in section, showing the lateral bends of the pipes and
heir horizontal continuations in end section; also the eduction pipe P, and the
nanner in which it ascends into the steam dome; lastly, the exit steam pipe,
nd the manner in which it passes through the chimney flue O. The super-

page_text: heating coil may be formed of copper pipe, but I prefer hollow wrought iron
pipes, such as are manufactured by drawing the best malleable iron. I do not
confine inyself to any particular form of the spiral or coil, or its disposition in
the fire box, although I find the form delineated in the Drawing the most.con-
venient for the description of boiler draivn. The coil may be made in two
parts to facilitate its introduction and adjustment in the fire box.
Figure 3 shows the fire box in plan; M, M', burner flues; N, N. exterior
of fire box; W. moveable lid or man-hole, secured by screw bolts, and
admitting of the introduction and adjustment of the superheating coil; P;
steam eduction pipe; P', steam escape pipe; Y, superheating coil; 0,
chimney fine.
Figure 4. front elevation of the boiler, part in section: A. A, shows the
double retort in section and in elevation, with the lid retaining screw I, J;
JJin-place-B, shows in section_the_cornice, which forms the sole of the
hearth fine and one of the brackets. which serve to support the retort: C
shows a side view of the hearth escape flue; and C' the hearth flue in section;
D is the hearth in section, with its fire bars. &c. These slope towards the end
of the boiler, as' in the ordinary boiler furnaces. E. ash-pit, in section; G.
fire door, in elevation with its sliding perforated plate for the admission and
regulation of the entrance of air to the hearth: G' is the ash door, in eleva-
tion with sliding perforated plate, &c.; H is a side view of the horizontal or
slightly inclined exit pipe. for the issue of the gas from the retort, and shows
its junction with the aerators L, L'; L, L', the face view of the funnel
months of the inner and outer aerator: M, burner flue in section, showing the
concentric arrangement of the gas pipe and aerators; also the collar m, by
which the burner flue is rivetted to the front plate or end of the boiler. The
end plate, which closes the burner fluc in front, and through which the con-
centric pipes from the retort and aerators pass and are collared is not rivetted,
but bolted on with screws to the collar m. so that it is capable of being
detached for the cleaning of the flues, should they require it; S, external cylinder
of boiler; T, internal cylinder or "generator;" R, man-hole; Q. steam box
or dome;,, sections of brackets and stays; and y. line on which the
section is taken in Figure 1. With regard to the supports for the boiler
where no side flues are employed I prefer simple brick piers at the front and
end, and in that case I cover the outside of the boiler with any of the ordi
nary insulators used to prevent loss of heat by radiation. An ordinary sheet
iron tube serves for all the chimney that I require, and I regulate its
dimensions and height by the size and proportions of the flues in the boiler.
In adapting the arrangement of boiler described to marine purposes I some

page_text: times dispose the tubes called the nerators, or at least the outer and principal
tube, in a manner so that their mouths or its mouth may be placed outside the
vessel in a position to receive a larger accession of air than can be obtained
merely from the furnace room. I also sometimes employ for marine uses a
double casing to the boiler, heating as in existing arrangements the feed water
by the radiant heat of the boiler, which might otherwise be lost.
Having now described the nature and disposition of the parts of my apparatus,
and the modifications I sometimes import, I proceed to describe the manner in
which the same is worked.
1 commence by making in the ordinary manner a coke or partly coke and
coal fire on the fire-bars, and when the bottom of the compartments of the
retort are heated by the said fire to dull redness, charge one of the said
compartments with the fuel to be burnt, which may be either coal, lignite,
peat, or wood, in fact any species of fuel capable of yielding a gaseous product
and leaving after the distillation of such gascous product a fixed carbon or
coke. After the gas begins to come off from the charged compartment, which
is properly closed with its lid in the usual manner and with the usual pre-
cautions, as observed in the management of gas retorts, I charge the second
compartment of the retort precisely in a similar manner to which the first
is charged, that is to say, either with a shovel or scoop made to fit the interior
of the compartament, and of a length varying with the length of the retort;
this scoop contains the necessary charge for, the compartment, and by its use
much less time is consumed in charging as well as that the compartments
of the retorts are not so long exposed to the cooling action of the air. The
fact of the gas beginning to escape from the retort is ascertained by means of
a small pipe and jet, which I term the test pipe, inserted in the eduction pipe
of the retort behind the stop cock, which is always kept closed until the gas
burns at the jet with some pressure. When this is judged to be sufficiently
the case the stop cock on the gas pipe is opened and immediately the gas
inflames by means of the ignited gasus playing from the hearth into the burner
flue through the hearth escape flue." The process of distillation varies in its
time according to the nature of the fuel, but when the gas at the test pipe
shows the quantity coming off to be small the lid is quickly unscrewed,
the remaining gas in the compartment ignited before it forms an explosive
mixture with the air, and the glowing coke raked on to the "dead plate" of
the hearth, being guided in its descent by means of the coke deflector.
During the time that the emptied compartment is being recharged, the gas
is continuously coming off from the other compartment, so that no interruption
is offered to the heating effects produced in the boiler, one or other of the

page_text: burner flues always being in action. The inner aerator or air tube admits of
what takes place within the burner flues, being seen by looking down the tube,
and consequently by means of the stop cocks regulating the admission of air
and gas respectively, the gaseous constituents of any fuel may be burnt with
the greatest regard to the maximum heating effect coupled with the greatest
economy of the combustible. The same is true of the fuel burnt on the
hearth or fire-bars, the combustion of which may be regulated by the careful
management of the fire and ash-pit doors assisted by the deflector plates.
Inasmuch as not illuminating power, but heating power is desired for the
gasses produced in the retorts, I prefer the distillation to be conducted at
as high a temperature as is obtainable in the apparatus, and by which, as
is well known, the largest production of coke, hydrogen, and carbonic oxide
may be obtained to the prevention of the formation of condensible hydro-carbon
vapours, and which is exactly the result sought by my system, since the
purification of the gas is not attempted. I prefer to use the fuel in a divided
state, and therefore clean coal dust answers my purpose for the retorts better
than the use of large coal. As, however, a coal which will afford a good
coke contributes to the economy of my process, I prefer such. The con-
sumption of fuel upon the hearth will of course vary with the character of
the coke coming from the combustible employed in the retorts, but inasmuch
as it averages for coal from 15 to 20 per cent. of the coke obtained, suflicient
coke is at all times obtained from one of the compartments not only to con-
tinue in full activity the fire on the hearth, but also to leave a reserve which
the stoker can quench, and then supply from time to time to the fire-bats.
In applying the Invention to locomotives I proceed as follows:-In this
case I prefer to use a single and undivided retort, which place in the fire-
box of the locomotive in a slanting position, the month being towards the
fireman. This retort is capable of being opened both at the top and at the
bottom, so that a charge of coal or other fuel after having been introduced at
the top and parted with its yield of gas passes out at the bottom in the form
of coke on to the fire grate or bars of the fire-box. The mode of feeding the
retort is by means of a hopper and valve, so that the stoker or fireman has
no occasion at any time to do more than keep the hopper filled, and froin
time to time to open a similar valve situated at the bottom of the retort,
letting fall the coke, and then after the closing of this bottom valve to open
the upper valve and let fall the fresh charge from the hopper. The grate
or hearth in the fire-box is arranged in a sloping form, and consists of
three or four steps or separate series of fire-bars, the step immediately
beneath the valve of the retort being that nearest to the fire-door; by this

page_text: arrangement a more perfect combustion of the coke is obtained. The flue
from the fire grate passes in a serpentine form or spiral round the retort, and
then opens by a double channel in face of the tubes of the boiler. which are
arranged as in ordinary locomotives, and carry off the products of combustion
of the coke. The gas pipe from the retort also opens with its concentric
arrangement of aerators between the two channels for the escape of the grate
gases, which, as in the arrangement. already described for a stationary or marine
boiler, serve to inflame the retort gases. The mouths of the aerators are
situated at the side of the locomotive. receiving their current from the advance
of the machine against the wind, and for which purpose their funnel arrange-
ment can be reversed, when the locomotive may be reversed. In all other
respects the details and mode of working of my system or form of apparatus as
applied to locomotives with slight modifications are the same as already
described for stationary or marine boilers. With regard to the disposition of
the superheating apparatus, however, I dispose the eduction pipe of which I
place the receiving month in the steam dome. if such exist on the boiler, so
that it may be connected with the coil in front of the tubes, in what is now
termed the smoke box. Or I arrange the eduction pipe in the course of the
flue proceeding from the grate. As in the present construction of locomotives
I surround the fire box as far as is practicable with water, and thus convert it
into an integral part of the boiler.
The following are the advantages possessed by my method of the double
combustion and separation in the same apparatus of the gaseous and fixed
products of the destructive distillation of any raw fuel.
1st, the absence of the production of smoke.
2nd, a less quantity of any fuel is required to produce a given amount of
heat than where the crude fuel is burnt whole, and the most effective part, if
not nearly the whole sum of the caloric, is derived from the radiated heat pro-
ceeding from the combustion of the fixed carbon or coke.
3rd, the possibility of using coal dust and other pulverulent fuels which
cannot be utilised in the ordinary way with a furnace of fire bars, and by using
which in steamers a much larger amount of fuel can be carried in bunkers of
the same dimensions, besides avoiding the necessity of frequent coalings; to
say nothing of the difference in price of such fuel. The advantages from using
brown coal or lignite coal, coal dust, peat, &c., successfully in locomotives are
obvious.
4th, the economy obtained by superheating the steam by the waste products
of combustion in the apparatus itself, and using at the same time the heat so
employed to raise additional steam.

page_text: It will this be seen that the system embraces five new and important
methods of obtaining and applying heat.
First, consume and utilize simultaneously the fixed carbon or coke of any
species of solid fuel, together with the gaseous constituents of such fuel as may
be commonly yielded during what is termed the process of destructive dis-
tillation, so that the sum of the calorific power of each of the heat-giving
agents may be rendered practically effective.
Second, arrange my apparatus so that I may regulate the combustion of
the gascous constituents of the fuel, both by controlling the admission of air to
the place of combustion as well as the admission of the fuel itself. The value
of this arrangement will be apparent.
Third, employ upon the large scale the same mechanical disposition of
apparatus as exists in what is termed the argund lamp," and by which I
secure for the combustible products of the destructive distillation of any fuel,
the same perfect smokeless combustion as are obtained by ihat lamp.
Fourth, in applying any system of burning fuel to the vaporization of water
or the raising of steam, I arrange the parts and disposition of my boiler so
that the furnace or calorifactive portions of the apparatus may be as nearly
entirely surrounded as possible with the water to be heated, and so that the
utmost use may be made of the radiant heat, as well as heat of contact,
whether proceeding from the combustion of the solid or the gascous con-
stituents of the fuel.
Fifth, make use of the heat retained by the escaping products of com-
bustion to superheat the steam raised by the general calorific arrangements of
the apparatus by exposing that steam to the action of the heated gases in the
boiler and not out of it, as in the present devised arrangements for superheating
steam.
In witness whereof, I, the said Nicholas Wehnert, have hereunto sei my
hand and seal, this Fourteenth day of February, in the year of our
Lord One thousand eight hundred and sixty-one.
MICH WEINERT. (L.S.)