IMPROVEMENTS IN APPARATUS FOR HEATING AIR AND VENTILATING BUILDINGS, PARTS OF WHICH ARE APPLICABLE TO OTHER PURPOSES
Year: 1875

page_text: LETTERS PATENT to Edward Thomas Hughes, of the Firm of Hughes
and Son, Patent Agents, 123, Chancery Lane, London, for the
Invention of "IMPROVEMENTS IN APPARATUS FOR HEATING AIR AND
VENTILATING BUILDINGS, PARTS OF WHICH ARE APPLICABLE TO OTHER PURPOSES."
-A communication from abroad by Sidney Smith and George Anson
Bates, both of Worcester, State of Massachusetts, United States
of America.
Sealed the 3rd December 1875, and dated the 5th June 1875.
PROVISIONAL SPECIFICATION left by the said Edward Thomas
Hughes at the Office of the Commissioners of Patents, with his
Petition, on the 5th June 1875.
I, EDWARD THOMAS HUGHES, of the Firm of Hughes and Son,
Patent Agents, 123, Chancery Lane, London, do hereby declare the
nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR
HEATING AIR AND VENTILATING BUILDINGS, PARTS OF WHICH ARE APPLICABLE TO
OTHER PURPOSES," a communication to me from abroad by Sidney Smith

page_text: and George Anson Bates, both of Worcester, State of Massachusetts,
United States of America, to be as follows:-
This Invention relates to an improvement in apparatus for heating
and ventilating buildings, parts of which are applicable to steam boilers,
air heating furnaces, and furnace fires generally, and consists,-

page_text: notch 6 at the opposite side to which it is hinged. The object of this
door is to afford a convenient means for cleaning the grate, and to
avoid the usual necessary shaking of the grate, and it is done by
inserting the "poker" through the opening beneath the door G and
running it over the surface of the grate, that is, between the grate and
the coal, which so agitates or disturbs the coal as to cause the ashes to
be separated and fall through into the pit below, and if occasion requires
the removal of clinkers or other foreign material the door G may be
opened and such material be removed without necessarily bringing it
to the top of the fire, as is necessary in the common construction
of furnaces. By this construction the fire is much more perfectly and
easily cleared than by any agitation of the grate or "poking" from
below.
In the usual construction of furnaces it has been the practice to
support the grate directly from an attachment to the walls of the fire-
box, hence any expansion or contraction of one or the other seriously
damages the position of the grate and of the walls.
To
Again in such construction the replacing of the grate or its supports
when they have become defective by use is a difficult work, and
generally requires a removal of some portion of the fire-box.
obviate this difficulty the grate B is made of any desirable construction,
and on its inner end a trunion a¹ is formed, and on the bottom of the
furnace a support G₁ is placed extending up to the grate, and with a
seat d¹ for the trunion. This support depends entirely upon the bottom
of the ash-pit for its position and is independent of the walls throughout,
as seen in the Drawings. At the forward end of the grate a similar
support H³ is arranged to hold the grate in like manner as described for
the support G¹.
The trunnion is arranged, by preference, a little to one side of the
centre, so that more than half the weight of the grate shall be upon the
opposite side of the centre, and to hold the grate in a horizontal position
the support G¹ is provided with a lug e' upon which the grate will rest,
as seen in Fig. 3; the grate may therefor be dumped by turning to
the opposite side, and returning will rest upon the lug e¹. By this con-
struction the grate is so entirely independent of the walls of the furnace
or firebox that it will stand of itself even if those walls were entirely
removed; and should occasion require the removal of the grate or the
12

page_text: support, such isolation of these parts allows their removal without in any
way disturbing or interfering with the adjacent parts of the furnace.
In some classes of furnaces the furnace support may be dispensed
with by allowing the forward trunnion of the grate to take its bearing
in the frame, but such construction would in that case be open some-
what to the difficulties which have been mentioned, but the easy
removal of the grate and the rear support would in that case be as well
attained.. H is the smoke or heating flue which leads from the top of
This circuitous
the fire-box down in a circuitous passage to the exit H'.
passage is preferably formed from plates of soapstone laid upon a wall
of the same material, and transverse openings I formed between the
plates, through which the air to be heated passes in contact with the
plates, by which contact it is heated.
***
'
The furnace is surrounded by a wall in the usual manner for other
furnaces, leaving a space between the wall and the furnace proper as
the heating space. Air is admitted through a suitable opening 1' near
the bottom at one side to pass through the transverse flues I to the
opposite side, and return again, and so on, back and forth to the desired
extent, coming finally to the hot-air chamber I' at the top, from whence
it is taken by pipes to the registers in the usual manner.
In order to deflect or turn the inflowing air back and forth through
the flues deflecting plates Is are arranged, as seen in Fig. 2.
The air which enters the heating chamber from outside has usually
combined with it more or less dust or other foreign manner, which
renders such air injurious to health, and the heating of the air in this
condition only adds to the difficulty, to avoid which a filter K is intro-
duced into the passage for cold air composed of an open fibrous material
presenting a wool or wooly surface sufficiently open to permit the air to
pass freely through, but the wooly fibres retain all dust or other foreign
matter which the air may contain when it comes to the filter, and hence
the air which is heated is perfectly pure.
In order to produce perfect combustion it is essential that more or less.
atmosphere be directly mingled with the products of combustion above
the burning coal. To do this a fluer is arranged in the fire-box wall,
preferably in the rear, into which the external atmosphere is permitted
to flow, and from this flue into the fire-box more or less perforations 2

page_text: are made, through which currents of air will freely flow into the fire-box,
as indicated in Fig. 1, there to mingle with the products of and produce
most perfect combustion. This flue is best made from soapstone, but
may be from any other material.
To regulate the draught of the fire a projection or extension L is formed
on the exit pipe H', and from the pipe H¹ a vertical pipe L' extends up
and connects with the direct draught L, and thence leads to the
chimney. The direct draught L2 is provided with a damper by which
to turn the draught through the circuitous flue to the exit H¹.
On the extension L a circular grooved flange N is formed, and over
this a cover N' is set, see Fig. 5, the flange of the cover setting into the
groove in the ring, and to this a chain or cord N2 is attached, by which
the cover N¹ may be suspended above the ring, as denoted in broken
lines; thus suspended an opening is formed into the draught flue, and
through this cold air will rush to the flue and check the draught,
according to the quantity of air admitted, but when closed the check
ceases and the draught is unobstructed.
The groove in the ring is filled with oil or other suitable liquid, so
that when the flange rests therein the opening will be perfectly
closed.
Between the outlet H and the check a partition M is arranged
extending up into the vertical pipe a short distance so as to form as it
were two flues, both opening into the main 'flue, whereby the possibility
of the escape of gas from the furnace through the check when opened is
prevented.
Above the furnace proper a longitudinal boiler P is arranged with a
vertical extension P¹ down into the fire-box, as shown in Fig. 1,
this extension P¹ being the lower or principal heating part of the
boiler.
:
S
The side walls of the furnace are carried up each side of the boiler,
as at P³, Fig. 2, nearly to the water line,, but at a short distance from
the boiler, and the boiler is provided with a flange P³ which extends out
and rests upon these walls to support the boiler. This arrangement of
the walls affords a considerable space for the passage of the heat and the
products of combustion around the entire exposed surface of the boiler.
The front wall or bridge for the furnace is left down and straight across;

page_text: as at P, Fig. 3, but the rear wall P³ extends up to the flange P³ and
conforms to the shape of the boiler, leaving only a narrow space P³,
through which the products of combustion must pass. This method of
suspending the boiler so as to leave an open and clear space up to the
point where the boiler is suspended possesses a great advantage over the
usual method of setting boilers, that is to say, in the usual method
the wall is brought up into close contact with the boiler at the point of
suspension, thus leaving a space so narrow as to prevent all possible
circulation of heat around the adjacent portions of the boiler, and
thereby confining the heat to the lower part of the boiler where there is
sufficient room for circulation, but by constructing the boiler with the
flange P to extend out on to the distant walls a clear space for circu-
lation is attained up to these flanges, and the whole of the boiler below
the flanges properly exposed to the heat from the fire, and this full
effect is insured by making the forward bridge open, and closing up the
rear bridge P³ so as to leave only a narrow space, through which the
products of combustion may pass. This tends to spread the fire, or
rather draw it into close contact with the entire exposed surface.
The projection P¹ into the fire-box serves to spread or distribute the
fire more perfectly than when the end or surface of the boiler only is
exposed to the fire, but as such downward projection if left solid over
the fire would tend to produce a dead space upon the under surface of
this projection, and thereby prevent the full effect of the fire upon that
exposed end, the boiler is constructed with a flue E' upward through the
centre of this downward projection up into the boiler, thence turning
and running longitudinally to the smoke flue, thus creating a central
draught through the projection P', thereby greatly increasing the extent
of the direct radiating surface.
A single vertical flue is shown, but it will be evident that there may
be several small flues if preferred, but experience shows that a perfect
result is attained by a single central flue; it not only brings the heat
of the fire into direct and uninterrupted contact with the lower end of
the projection P' but extends the concentrated heat of the fire
throughout the length of the flue. This method of setting the boiler
and its construction is applicable to other furnaces and to boilers for
other purposes, and it will be understood that the other parts of the
furnace described are not dependent on nor essential to the boiler, but
in many cases it is desirable to combine with an air heating furnace a

page_text: boiler for steam heating purposes, and in such cases this arrangement
of the boiler produces the most satisfactory result.
The upper part of the boiler is left open or exposed in the hot air
chamber above the furnace, and to that extent may act as a superheater
for the air which has already passed through the furnace.
The prime object of the combination of the boiler with the air-heating
furnace is to take the steam or hot water, as the case may be, from the
boiler to radiators at a point where it is difficult or impossible to reach
by the air heating flues. ;
Radiators or heating surfaces are usually made from a series of cast
sections pipes or from thin sheet metal, as in that known as the Gold
Patent. In all cases dependence is placed entirely upon the natural
radiation upon the surrounding atmosphere without creating any
artificial circulation.
Again in all these constructions there are extensive or numerous
joints which are liable to leak, causing a constant necessity for repairs
and great annoyance and inconvenience to those depending upon them
for heat. As is the radiator here represented as three corrugations only,
but may be extended to an indefinite extent. This is cast complete and
close throughout the corrugations, being substantially vertical and
constitutes the steam or heating chamber, and hence has no joints to
leak or become defective. Steam is admitted and the condensation
drawn off in the usual manner. This radiator is set upon a suitable
base B³, through which are apertures a³, each opening into one of the
spaces or corrugations in the radiator, and upon the base the casing
C³ is set, and this is close except at the top where perforations d² are
made and the whole crowned by a cap D‘.
The perforations d' may be in the cap, it only being essential that
they shall be at or very near the top of the heating chamber. The corru-
gations in the heating chamber thus constitute flues through which the
air is drawn from the bottom and discharged at the top, the radiation
from the surface constituting the force to draw the air through these
flues, instead of depending upon the natural contact of the surrounding
atmosphere with the heating surface as in the usual construction. This
construction gives a very large amount of direct radiating surface within
a given space, and insures a constant circulation of air.
In order to introduce air from outside to the radiator and at the same

page_text: time to force a circulation of the atmosphere in the room, a flue or pipe
E leads from the outside. to the radiator, and this is divided so as to
carry to each of the openings a³ in the base a flue d', of less diameter
than the openings a³, so that while the external air will pass in through
these smaller flues to be heated and pass off, the air from the lower part
of the room will be drawn into the openings at around the pipes d', and
thus keep up a constant circulation of the air in the room as well as a
constant supply of fresh air.
'
The pipe E' may be provided with a damper by which to cut off the
admission of the external air if at any time it should be desirable.
It will be understood that hot water may be employed instead of
steam if desired, with the same result. The expression steam therefore
is to be understood as including hot water.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Edward Thomas Hughes in the Great Seal Patent 1
Office on the 4th December 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWARD
THOMAS HUGHES, of the Firm of Hughes and Son, Patent Agents, 123,
'Chancery Lane, London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her 2
Letters Patent, bearing date the Fifth day of June, in the year of our
Lord One thousand eight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Edward Thomas Hughes, Her special
licence that I, the said Edward Thomas Hughes, my executors, admi- 2
nistrators, and assigns, or such others as I, the said Edward Thomas
Hughes, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after 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 Inven-
tion for "IMPROVEMENTS IN APPARATUS FOR HEATING AIR AND VENTILATING
BUILDINGS, PARTS OF WHICH ARE APPLICABLE TO OTHER PURPOSES," a commu-

page_text: In the Drawings Fig. 1 is a longitudinal central section; Fig. 2,
transverse section on line x, x; Fig. 3, transverse section on line 2, 2;
Fig. 4, perspective view of the grate detached; Fig. 5, vertical section
of the draught regulator; Fig. 6, front view of the radiator; Fig. 7,
transverse section, and Fig. 8, vertical section of the same.
A is the fire-box, the fire supported on a grate B, beneath which is an
ash-pit C, the ash-pit closed by a door D; E, the door closing the
opening E' to the fire-box. Between the ash-pit door and the fire
opening, and on a level with the upper surface of the grate is a third
opening F closed by a door F'. At the inside of the front wall, and in
this opening F is an auxiliary door G, shown in Fig. 4; beneath this
door is an opening a flush with the grate; the door held closed by
latching into a notch 6 at the opposite side to which it is hinged; the
object of this door is to afford a convenient means for cleaning the grate,
and to avoid the usual necessary shaking of the grate, and it is done by
inserting the "poker" through the opening beneath the door G, and
running it over the surface of the grate, that is, between the grate and
the coal which so agitates or disturbs the coal as to cause the ashes to
be separated and fall through into the pit below, and if occasion
requires the removal of clinkers or other foreign material the door G
may be opened, and such material be removed without necessarily
bringing it to the top of the fire, as is necessary in the common con-
struction of furnaces. By this construction the fire is much more
perfectly and easily cleaned than by any agitation of the grate or
"poking" from below.
In the usual construction of furnaces it has been the practice to
support the grate directly from an attachment to the walls of, the fire-
box, hence any expansion or contraction of one or the other seriously
deranges the position of the grate and of the walls.
Again, in such construction the replacing of the grate or its supports
when they have become defective by use is a difficult work, and
generally requires a removal of some portion of the fire-box. To obviate
this difficulty the grate B is made of any desirable construction, and on
its inner end a trunnion a¹ is formed, and on the bottom of the furnace
a support G¹ is placed extending up to the grate, and with a seat ď¹³ for
the trunnion; this support depends entirely upon the bottom of the ash-
pit for its position, and is independent of the walls throughout, as seen

page_text: iu the Drawings. At the forward end of the grate a similar support H*
is arranged to hold the grate in like manner, as described for the
support G¹.
The trunnion is arranged, by preference, a little to one side of the
centre, so that more than half the weight of the grate shall be upon the
opposite side of the centre, and to hold the grate in a horizontal position,
the support G is provided with a lug e' upon which the grate will rest,
as seen in Fig. 3; the grate may therefore be dumped by turning to the
opposite side, and returning will rest upon the lug e¹. By this con-
struction the grate is so entirely independent of the walls of the furnace
or fire-box that it will stand by itself, even if those walls were entirely
removed, and should occasion require the removal of the grate on the
supports such isolation of these parts allows their removal without in
any way disturbing or interfering with the adjacent parts of the
furnace.
In some classes of furnaces the forward support may be dispensed
with by allowing the forward trunnion of the grate to take its bearing
in the frame, but such construction would in that case be open some-
what to the difficulties which have been mentioned, but the easy
removal of the grate and the rear support would in that case be as well
attained. His the smoke or heating flue which leads from the top of
the fire-box down in a circuitous passage to the exit H¹. This circuitous
passage is preferably formed from plates of soapstone laid upon a wall
of the same material, and transverse openings I formed between the
plates through which the air to be heated passes in contact with the
plates, by which contact it is heated.
_ _
The furnace is surrounded by a wall in the usual manner for other
furnaces, leaving a space between the wall and the furnace proper as the
heating space. Air is admitted through a suitable opening I' near the
bottom at one side to pass through the transverse flues I to the opposite
side and return again, and so on back and forth to the desired extent,
coming finally to the hot-air chamber I at the top, from whence it is
taken by pipes to the registers in the usual manner.
In order to deflect or turn the inflowing air back and forth through
the flues deflecting plates I³ are arranged, as seen in Fig. 2.
The air which enters the heating chamber from outside has usually
combined with it more or less dust or other foreign matter which renders

page_text: such air injurious to health, and the heating of the air in this condition
only adds to the difficulty, to avoid which a filter K is introduced into
the passage for cold air composed of an open fibrous material presenting
a wool or woolley surface sufficiently open to permit the air to pass freely
through; but the woolley fibres retain all dust or other foreign matter
which the air may contain when it comes to the filter, and hence the
air which is heated is perfectly pure.
In order to produce perfect combustion it is essential that more or
less atmosphere be directly mingled with the products of combustion
above the burning coal. To do this a flue is arranged in the fire-box
wall, preferably in the rear, into which the external atmosphere is
permitted to flow, and from this flue into the fire-box more or less
perforations 2 are made, through which currents of air will freely flow
into the fire-box, as indicated in Fig. 1, there to mingle with the products
of and produce most perfect combustion. This flue is best made from
soapstone, but may be from any other material.
To regulate the draught of the fire a projection or otherwise L is
formed on the exit pipe H¹, and from the pipe H' a vertical pipe L'
extends up and connects with the direct draft L³, and thence leads to the
chimney. The direct draft L³ is provided with a damper 6 by which
to turn the draft through the circuitous flue to the exit H.
b
On the extension La circular grooved flange N is formed, and over
this a cover N¹ is set, see Fig. 5, the flange of the cover setting into the
groove in the ring, and to this a chain or cord N³ is attached, by which
the cover N¹ may be suspended above the ring, as denoted in broken
lines; thus suspended an opening is formed into the draft flue, and
through this cold air will rush to the flue and check the draught
according to the quantity of air admitted, but when closed the check
ceases and the draught is unobstructed.
The groove in the ring is filled with oil or other suitable liquid,
so that when the flange rests therein the opening will be perfectly
closed.
Between the outlet H¹ and the check a partition M is arranged
extending up into the vertical pipe a short distance so as to form, as it
were, two flues, both opening into the main flue, whereby the possi

page_text: bility of the escape of gas from the furnace through the check when
opened is prevented.
Above the furnace proper a longitudinal boiler P is arranged, with a
vertical extension P¹ down into the fire-box, as shown in Fig. 1; this
extension P¹ being the lower or principal heating part of the boiler.
The side walls of the furnace are carried up each side of the boiler,
as at P, Fig. 2, nearly to the water line, but at a short distance from
the boiler, and the boiler is provided with a flange P³, which extends
out and rests upon these walls to support the boiler. This arrangement
of the walls affords a considerable space for the passage of the heat and,
the products of combustion around the entire exposed surface of the
boiler. The front wall or bridge for the furnace is left down and straight
across, as at P*, Fig. 3, but the rear wall P' extends up to the flange P³
and conforms to the shape of the boiler, leaving only a narrow space. P³,
through which the products of combustion must pass. This method of
suspending the boiler so as to leave an open and clear space up to the
point where the boiler is suspended, possesses a great advantage over tho
usual method of setting boilers, that is to say, in the usual method the
wall is brought up into close contact with the boiler at the point of
suspension, thus leaving a space so narrow as to prevent all possible
circulation of heat around the adjacent portions of the boiler, and
thereby confining the heat to the lower part of the boiler, where there
is sufficient room for circulation, but by constructing the boiler with the
flange P to extend out on to the distant walls a clear space for circu-
lation is attained up to these flanges, and the whole of the boiler below
the flanges properly exposed to the heat from the fire, and this full
effect is ensured by making the forward bridge open and closing up the
rear bridge P³ so as to leave only a narrow space through which the
products of combustion may pass; this tends to spread the fire or rather
draw it into close contact with the entire exposed surface.
The projection P¹ into the fire-box serves to spread or distribute the
fire more perfectly than when the end or surface of the boiler only is
exposed to the fire, but as such downward projection is left solid over
the fire would tend to produce a dead space upon the under surface of
this projection, and thereby prevent the full effect of the fire upon that
exposed end. The boiler is constructed with a flue E' upward through
the centre of this downward projection, up into the boiler, thence
turning and running longitudinally to the smoke flue, thus creating

page_text: a central draught through the projection P¹, thereby greatly increasing
the extent of the direct radiating surface.
A single vertical flue is shown, but it will be evident that there may
be several small flues if preferred; but experience shows that a perfect
result is attained by a single central flue; it not only brings the heat
of the fire into direct and uninterrupted contact with the lower end of
the projection P¹, but extends the concentrated heat of the fire
throughout the length of the flue. This method of setting the boiler
and its construction is applicable to other furnaces, and to boilers
for other purposes, and it will be understood that the other parts of
the furnace described are not dependent on nor essential to the boiler;
but in many cases it is desirable to combine with an air heating furnace
a boiler for steam heating purposes, and in such cases this arrangement
of the boiler produces the most satisfactory result.
The upper part of the boiler is left open or exposed in the hot air
chamber above the furnace, and to that extent may act as a super-
heater for the air which has already passed through the furnace.
The prime object of the combination of the boiler with the air heating
furnace is to take the steam or hot water, as the case may be, from the
boiler to radiators at a point where it is difficult or impossible to reach
by the air heating flues.
Radiators or heating surfaces are usually made from a scries of cast
sections, pipes, or from thin sheet metal, as in that known as the Gold
Patent. In all cases dependence is placed entirely upon the natural,
radiation upon the natural atmosphere without creating any artificial 1
circulation.
Again, in all these constructions there are extensive or numerous
joints which are liable to leak, causing a constant necessity for repairs,
and great annoyance and inconvenience to those depending upon them
for heat. A³ is the radiator, here represented as having three corru-
gations only, but may be extended to an indefinite length. This is
cast complete and close throughout, the corrugations being substantially
vertical, and constitutes the steam or heating chamber, and hence has
no joints to leak or become defective. Steam is admitted and the
condensation drawn off in the usual manner. This radiator is set 3
upon a suitable base B³ through which are apertures a³, each opening

page_text: into one of the spaces or corrugations in the radiator, and upon the
base the casing C³ is set, and this is close except at the top, where per-
forations d' are mad, and the whole crowned by a cap D'.
The perforations d' may be in the cap, it only being essential that
they shall be at or very near the top of the heating chamber. The
corrugations in the heating chamber thus constitute flues, through
which the air is drawn from the bottom and discharged at the top, the
radiation from the surface constituting the force to draw the air through
the flues instead of depending upon the natural contact of the sur-
rounding atmosphere with the heating surface, as in the usual con-
struction. This construction gives a very large amount of direct
radiating surface within a given space, and insures a constant cir-
culation of air.
In order to introduce air from outside to the radiator, and at the
same time to force a circulation of the atmosphere in the room, a flue
or pipe E leads from the outside to the radiator, and this is divided
so as to carry to each of the openings a³ in the base a flue d' of less
diameter than the openings a³, so that while the external air will pass
in through these smaller flues to be heated and pass off, the air from
the lower part of the room will be drawn into the openings a³, around
the pipes d', and thus keep up a constant circulation of the air in the
room, as well as a constant supply of fresh air.
The pipe E may be provided with a damper by which to cut-off
admission of the external air if at any time it should be desirable.
It will be understood that hot water may be employed insted of
steam, if desired, with the same result. The expression steam therefore
is to be understood as including hot water.
Having now described the nature and particulars of the said In-
vention, I claim,―
First. A steam boiler constructed with a projection P¹ down into
the fire-box combined with a vertical flue through said projection,
turned through the longitudinal portion of the boiler, and leading to
the smoke flue, substantially as described.
Second. In combination with the fire-box and ash-pit of a furnace
and their respective openings, the auxiliary opening F between the fire

page_text: the open bridge at the fire-box and the close bridge P' at the rear,
forming a passage for the escape of the products of combustion close
around the boiler at said rear bridge, substantially as and for the
purpose described.
.
Thirteenth. In combination with the fire-grate of a furnace the inner
support Gindependent of and isolated from the adjacent walls or parts.
of the furnace, substantially as set forth.
Fourteenth. The herein-described radiator for steam heating, con-
sisting of a series of continuous or connected vertical corrugations
formed complete and together in one casting, and close except for the
steam inlet and exit, substantially as set forth.
Fifteenth. The herein-described radiator for steam heating, consisting
of the vertically corrugated steam chamber combined with a close
enclosing case with openings into the corrugations through the base
and at the top, substantially as described, whereby the said corrugations
form heating flues to force a circulation of the atmosphere, substantially
as specified.
Sixteenth. In combination with a steam radiator, consisting of a
series of flues, the air supply flues d' of less diameter than the
openings into the radiator, substantially as and for the purpose
specified.
In witness whereof, I, the said Edward Thomas Hughes, have
hereunto set my hand and seal, this Third day of December,
One thousand eight hundred and seventy-five.