IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUSES AND IN MACHINERY FOR OBTAINING AND APPLYING HEATED AIR TO FURNACES FOR THE CONSUMPTION OF SMOKE AND THE SAVING OF FUEL, IMPROVING VENTILATION IN ROOMS, DRYING ANIMAL
Year: 1872

page_text: LETTERS PATENT to George Rydill, of Grove House, Dewsbury, in the
County of York, Merchant, for the Invention of "IMPROVEMENTS
IN THE CONSTRUCTION OF APPARATUSES AND IN MACHINERY FOR OBTAINING
AND APPLYING HEATED AIR TO FURNACES FOR THE CONSUMPTION OF SMOKE
AND THE SAVING OF FUEL, IMPROVING VENTILATION IN ROOMS, DRYING ANIMAL
Sealed the 11th February 1873, and dated the 24th December 1872.
PROVISIONAL SPECIFICATION left by the said George Rydill at the
Office of the Commissioners of Patents, with his Petition, on the
24th December 1872.
I, GEORGE RYDILL, of Grove House, Dewsbury, in the County of
York, Merchant, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN THE CONSTRUCTION OF APPARATUSES AND IN MACHINERY FOR
OBTAINING AND APPLYING HEATED AIR TO FURNACES FOR THE CONSUMPTION OF
SMOKE AND THE SAVING OF FUEL, IMPROVING VENTILATION IN ROOMS, DRYING
ANIMAL AND VEGETABLE SUBSTANCES, AND IN THE CONSTRUCTION OF FURNACES," to
be as follows :—
My Invention of improvements are to effectually remedy the evils of
the introduction of cold air to grate bar furnaces, furnace doors, and at

page_text: the end of grate bars near the bridge to effect combustion, and to
consume smoke. Engineers and scientific men have hitherto recom-
mended the introduction of cold air for this purpose.
This my Invention is to effectually introduce hot air underneath the
grate bars and over the door for the consumption of smoke and the
saving of fuel obtained, and applied in the following manner :-
First. By placing the chimney from 5 to 50 yards or more away from
the boiler or furnace. In most instances at present the heat from the
furnace or boiler is allowed to travel along the flue and into the chimney
with some exceptions, when what are called fuel economisers have been
introduced into the flues for heating water provious to entering tho
boiler, the boiling point of water being 212 degrees, but it is rare that
the water in the economiser tubes reaches more than 180 degrees of heat
in ordinary working. Now the products of combustion are mostly
escaping through the flue into the chimney at from 600 to 700 degrees
of heat, and my improvements for which I am now applying for Letters
Patent may increase the heat even to 800 degrees or more in the fluc,
and as water cannot be heated to more than 212 degrees of heat in the
flues my improved Invention is to supersede water tubes in the flues and
to obtain heated air by the action of the waste products of combustion
as they are passing along the flue and up the chimney by inserting air
tubes or forming air passages in the flues and chimney, and enabling me
to raise atmospheric air 'made to pass through those air tubes and
passages to a temperature of from 400 to 600 degrees of heat, or probably
even to a higher temperature, according to the condition of the furnace,
and I allow this heated air so obtained to act in sufficient quantitics
upon the fuel through the grate bars and over the fire to effect the
perfect combustion and consumption of smoke. Heated air so obtained
I. apply also for the burning of hydrocarbon oils such as petroleum,
naptha, or gases, for raising steam or for heating purposes. In case the
chimney is near the boiler end of the furnace I form the flue from the
end of the boiler in a circuitous route in order to obtain some length of
fluc before reaching the chimney. So as to describe my Invention fully
and clear I place iron or other metal round the bottom of the chimney
forming an elbow tube, and one elbow flange projects from the bottom
of the chimney into the flue, and the other elbow flange stands perpen-
dicular in the chimney bottom. An air space is formed round the sides
and at the bottom of said elbow, which is made to stand upon feet,

page_text: brackets, or brickwork, and I continue to place one tier of tubes in a
circular or square form according to the build of the chimney, placing
one tier of tubes on the top of the other drawn up in one or more parts,
and securing the same one to each other with bolts, always leaving a
space of some inches, say from 2 to 6 inches round the outer casing of
the tubes and the inside chimney wall, and these tubes may be continued
to any convenient height in the chimney. These tubes contain openings
with a projecting flange so as to fix hollow conical or other shaped tubes
across from one side of the tube to the other in a slanting or other
position, allowing the air in its descent to cross backwards and forwards.
A flange closes in the top end of the tube so as to prevent the heated
products of combustion passing up through the tube from entering the
hollow air space. A course of brickwork I build in cement round the
top flange of the tube. Air grates I fix near the top of the tubes to
admit fresh air through the chimney walls. The air enters through
these air passages, and the heated products of combustion passing up
the inside of the tubes heats the air entering from the outside of the
chimney in its passage down through the hollow air spaces to the bottom
of the chimney. The elbow tube fixed at the bottom of the chimney is
connected to other tubes which are supported by brackets and arched all
round, leaving air passages of some inches round the tubes. I also
insert in those tubes the products of combustion, conical or other shaped
air tubes similar to those placed across the tubes fixed in the chimney,
causing the heated products in the flue to strike against the tubes pro-
curing additional heating surface for the heated air. This form of air
passages is continued until it reaches the boiler or furnace, such for
instance as a Cornish boiler. The hot air tubes or passages I continue
underneath the bottom or sides of the boiler, the heated products of
combustion escaping from the boiler flue, adding further heat to the air
tube; or on the hot air tube reaching the end of the boiler the heated
air may be made to rise up and pass over the top of the boiler, the boiler
being arched over, forming an air passage and conducting the hot air by
means of a tube to the furnace; or the heated air may be conducted in
any other convenient way to a convenient space underneath the furnace
or fire-box of a Cornish or other boiler furnace. The cold atmospheric air
rushes into the openings in the chimney or fluc to take place of the
heated entering the furnace, and causing the heated air of some
hundreds of degrees of licat to travel with great velocity along the air
passages and act as a fan blast upon the fire, preventing the injurious

page_text: effects of admitting cold air to furnaces, and in order to raise any
required temperature in the furnace I conduct the heated air to a fan to
act upon the furnace so that one furnace may be made to supply heat to
several boilers..
The circular air passages formed in the chimney may be built of
brick for cheapness instead of metal, and hollow metal tubes cross from
one side of the hollow space to the other in a slanting position
so that the current of air may cross in various directions in its
descent.
The form of the air passages in the flue may be either square, round,
oval, or longitudinal; pipes made of metal or any other material, or a
kind of hollow shelves fixed one above the other may be built in the
flue leaving air passages, and with divisions built on one side of the air
passages causes the air to pass through the tubes to the other side,
and divisions built first on one side of the tube and then on the other
causes the heated air to travel in a serpentine or other direction to the
furnace. But I prefer placing hollow metal pipes fitted into the top
of a kind of metal box or plate placed at the bottom of the fluc, the
hollow pipes being secured to the holes in the box or plate standing in
various positions; but perpendicular and on the top of those pipes I
fix a metal plate or box, the pipes entering in at the bottom of the box,
and a tight joint is made by a metal ring. The height of the metal
box is so elevated as to give sufficient room for air rising up from the
hollow space underneath, which heated air for instance rises up say
twenty hollow pipes or tubes, and on entering the hollow box or air
space at the top another twenty hollow pipes or tubes in the same box
or air space conducts the heated air to an air space formed underneath,
and another twenty pipes or tubes fixed in the air space at the bottom
of the flue allows the air to ascend. In this way the air ascends and
descends through some hundreds of tubes causing the air to traverse in
a serpentine direction, causing the air to become heated by the heated
products of combustion passing amongst and around the tubes on its
way to the chimney, causing the air which first entered the air passages
fixed in the chimney or flue to be raised in temperature in passing
through the pipes or tubes, and delivering the heated air into the tube
leading to the furnace at some at some hundreds of degrees of heat. Pro-
viding it is found requite to assist the air in its travel through the tubes for
heating the air for the furnace or for drying purposes, I place a fau

page_text: cither to force or draw the air through the tubes, or an air cylinder
engine may be employed for forcing and drawing air through the tubes
or through a hollow jacketed or double cased flue in the form of letter
D, made of either metal or any other material, obtaining heated air
from the waste products of combustion in the chimney or flues. The
pipes or tubes fixed in the flues will require to be built in with brick-
work, or cased with iron, having suitable door openings on the inside of
the chimney clbow tube, so that any accumulation of dust or dirt can
be removed; also doors are fixed at side or sides of flues, so that the
soot or dust can be removed which may have accumulated at the bottom
of flue and amongst the pipes or tubes by the action of what are known
as travelling scrapers in fuel economisers.
This improved method of procuring heated air I apply to marine
steam boiler furnaces by forming a hollow casing round the funnel or
any other part of the boiler or boilers, and conducting the air entering
the hollow air tube near the top of the chimney to the furnace or
furnaces, and the air from cach room or cabin I conduct by a tube or
tubes to the jacketed air space, a suction being formed by the furnace
procures ventilation in each room or cabin throughout the ship.
I also fix metal or other tubes in the chimney of dwelling-houses,
leaving an air space all round the tube, having an outlet coming in
connection with the under side of the firc-grate, and extending up the
chimney to near the top; the air enters through a grating fixed in the
chimney, heating the air in its descent, which may be conducted into
various rooms on its downward course for warming and ventilation
purposes, or the air may wholly be conducted underneath the fire-
grate.
This my improved Invention is applicable to every description of
furnace, such as the furnaces under dye pans, brewing pans, brick kilns,
or for other purposes, when a fire and chimney is crected; at some of
the large factories where a number of steam boilers are worked the
heated products of combustion on leaving the boiler are made to enter
one flue and pass up the chimney. My object is to distribute the heated
products over a larger area of flue until it reaches the chimney bottom;
this enables me to procure a large heating surface for obtaining heated
air, in some cases the heated products of combustion may be made to
uct upon crossed piles of pig iron or brickwork in a suitable confined

page_text: space with a view to heat the same, then abstract the heat with cold air
for drying purposes.
This improved method or methods of obtaining and applying heated
air to furnaces, raising steam, drying purposes, and ventilating rooms, is
procured at no cost beyond the first outlay, and effectually consumes the
smoke in furnaces. Or I place in the flue a number of tubes resting at
the ends of the tubes in two pierced plates, similar to the two ends of a
locomotive boiler for the heating products of combustion to pass through,
allowing the atmospheric air to act on the outside of the tubes in order
to heat the air; at the end of the tubes a square or circular metal box is
fixed, having one or more well-fitted hinged doors; when opened the
products of combustion enter through the doors into the box, then
through the tubes, and as these tubes are liable to make up with soot or
dust from the furnace I close the door or doors on the inside of the box,
and having a steam pipe leading into the box with valve I open the
steam valve, which presses close the door or doors to the openings, and
in three seconds the tubes are cleaned out, the door or doors are again
opened, and the heated products of combustion again are drawn through
the tubes on their way to the chimney, the heated air being carried
forwards to the furnace.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said George Rydill in the Great Seal Patent Office
on the 24th June 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, George
RYDILL, of Grove House, Dewsbury, in the County of York, Merchant,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-fourth day of December, in the year of our
Lord One thousand eight hundred and seventy-two, in the thirty-sixth
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said George Rydill, Her special licence that I, the
said George Rydill, my executors, administrators, and assigns, or such
others as I, the said George Rydill, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to timo

page_text: 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 THE CONSTRUCTION OF APPARATUSES
AND IN MACHINERY FOR OBTAINING AND APPLYING HEATED AIR TO FURNACES FOR
THE CONSUMPTION OF SMOKE AND THE SAVING OF FUEL, IMPROVING VENTILATION IN
ROOMS, DRYING ANIMAL AND AND VEGETABLE SUBSTANCES, AND IN THE CONSTRUCTION
OF FURNACES," upon the condition (amongst others) that I, the said George
Rydill, 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 Invention, and in what
manner the same was to be performed, and cause the same to be filed
in the Great Seal Patent Office within six calendar months next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said George Rydill, do hereby declaro
the nature of my said Invention, and in what manner the same is to
be performed, to be particularly described and ascertained in and by
the following statement :-
1!
My Invention of improvements are to effectually remedy the evils of
the introduction of cold air to grate bar furnaces, furnace doors, and
at the end of grate bars near the bridge, to effect combustion and to
consume smoke. Engineers and scientific men have hitherto recom-
mended the introduction of cold air for this
purpose.
This my Invention is to effectually introduce hot air underneath
the grate bars and over the door for the consumption of smoke and
the saving of fuel, obtained and applied in the following manner :-
First. By placing the chimney from five to fifty yards or more away
from the boiler or furnace. In most instances at present the heat from the
furnace or boiler is allowed to travel along the flue and into the chimney,
with some exceptions, when what are called fuel economisers have been
introduced into the flues for heating water previous to entering the
boiler, the boiling point of water being 212 degrees, but it is rare that
the water in the economiser tubes reaches more than 180 degrees of heat
in ordinary working. Now the products of combustion are mostly
escaping through the fluc into the chimney at from 600 to 700 degrees
of heat, and my improvements, for which I am now applying for Letters
Patent, may increase the heat even to 500 degrees or more in the fluc,

page_text: .
and as water cannot be heated to more than 212 degrees of heat in the
flues my improved Invention is to supersede water tubes in the flues and
to obtain heated air by the action of the waste products of combustion
as they are passing along the flue and up the chimney; by inserting
air tubes or forming air passages in the flues and chimney, and enabling
me to raise atmospheric air made to pass through those air tubes and
passages to a temperature of from 400 to 600 degrees of heat, or probably
even to a higher temperature, according to the condition of the furnace,
and I allow this heated air so obtained to act in sufficient quantities
upon the fuel through the grate bars and over the fire to effect the
perfect combustion and consumption of smoke. Heated air so obtained
I apply also for the burning of hydrocarbon oils, such as petroleum,
naphtha, or gases, for raising steam or for heating purposes. In case the
chimney is near the boiler end of the furnace I form the flue from the
end of the boiler in a circuitous route in order to obtain some length of
flue before reaching the chimney. So as to describe my Invention fully
and clear I place iron or other metal round the bottoin of the chimney.
forming an elbow,tube, and one elbow flange projects from the bottom
of the chimney into the flue, and the other elbow flange stands perpen-
dicular in the in the chimney bottom; an air space is formed round the
sides and at the bottom of said elbow which is made to stand upou feet,
brackets, or brickwork, and I continue to place one tier of tubes in a
circular or square form, according to the build of the chimney, placing
one tier of tubes on the top of the other, drawn up in one or more parts
and securing the same one to each other with bolts, always leaving
a space of some inches say from two to six inches round the outer casing
of the tubes and the inside chimney wall, and these tubes may be.
continued to any convenient height in the chimney. These tubes
contain openings with a projecting flange, so as to fix hollow, conical, or
other shaped tubes across from one side of the tube to the other in a
slanting or other position, allowing the air in its descent to cross
'backwards and forwards. A flange closes in the top end of the tube so
as to prevent the heated products of combustion passing up through the
tube from entering the hollow air space; a course of brickwork I build
in cement round the top flange of the tube; air grates I fix near the top
of the tubes to admit fresh air through the chimney walls. The air
enters through these air passages and the heated products of combustion
passing up the inside of the tubes heats the air entering from the outside
of the chimney in its passage down through the hollow air spaces to the

page_text: bottom of the chimney. The elbow tube fixed at the bottom of the
chimney is connected to other tubes which are supported by brackets
and arched all round, leaving air passages of some inches round the
tubes. I also insert in those tubes conveying the products of combustion,
conical or other shaped air tubes, similar to those placed across the tubes
fixed in the chimney, causing the heated products in the flue to strike
against the tubes, procuring additional heating surface for the heated
air. This form of air passages is continued until it reaches the boiler or
furnace, such for instance as a Cornish boiler. The hot air tubes or
passages I continue underneath the bottom or sides of the boiler, the
heated products of combustion escaping from the boiler flue adding
further heat to the air tube, or on the hot air tube reaching the end of
the boiler the heated air may be made to rise up and pass over the top
of the boiler, the boiler being arched over, forming an air passage and
conducting the hot air by means of a tube to the furnace, or the heated
air may be conducted in any other convenient way to a confined space
underneath the furnace or fire-box of a Cornish or other boiler furnace.
The cold atmospheric air rushes into the openings in the chimney or flue
to take the place of the heated air entering the furnace, and causing
the heated air of some hundreds of degrees of heat to travel with great
velocity along the air passages, and act as a fan blast upon the fire,
preventing the injurious effects of admitting cold air to furnaces; and in
order to raise any required temperature in the furnace I conduct the
heated air to a fan to act upon the furnace so that one furnace may be
made to supply heat to several boilers if desirable.
The circular air passages formed in the chimney may be built of brick,
for cheapness, instead of metal, and hollow metal tubes cross from one
side of the hollow space to the other in a slanting position, so that the
current of air may cross in various directions in its descent.
The form of the air passages in the flue may be either square, round,
oval, or longitudinal pipes made of metal or any other material, with
divisions built on one side of the air passages causes the air to pass
through the tubes to the other side, and divisions built first on one side
of the tube and then on the other causes the heated air to travel in a
serpentine or other direction to the furnace. But I prefer placing
hollow metal pipes fitted into the top of a kind of metal box or plate
placed at the bottom of the flue, the hollow pipes being secured to the
holes in the box or plate standing in various positions, but perpendicular,

page_text: and on the top of those pipes I fix a metal plate or box, the pipes
entering in at the bottom of the box, and a tight joint is made by a
metal ring. The height of the metal box is so elevated as to give
sufficient room for air rising up from the hollow space, underneath
which heated air, for instance, rises up, say, twenty hollow pipes or
tubes, and on entering the hollow box or air space at the top another
twenty hollow pipes or tubes in the same box or air space conducts the
heated air to an air space formed underneath, and another twenty pipes
or tubes fixed in the air space at the bottom of the flue allows the air to
ascend. In this way the air ascends and descends through some hundreds.
of tubes, causing the air to traverse in a serpentine direction, causing the
air to become heated by the heated products of combustion passing
amongst and around the tubes on its way to the chimney, causing the
air which first entered the air passages fixed in the chimney or flue to be
raised in temperature in passing through the pipes or tubes, and
delivering the heated air into the tube leading to the furnace at some
hundreds of degrees of heat. Providing it is found requisite to assist the
air in its travel through the tubes for heating the air for the furnace,
or for drying purposes, I place a fan, either to force or draw the air
through the tubes, or an air cylinder engine may be employed for
forcing and drawing air through the tubes or through a hollow, jacketed,
or double cased flue in the form of letter D, made of either metal or any
other material, obtaining heated air from the waste products of com-
bustion in the chimney or flues. The pipes or tubes fixed in the flues
will require to be built in with brickwork, or cased with iron, having
suitable door openings on the inside of the chimney elbow tube, so that
any accumulation of dust or dirt can be removed. Also doors are fixed
at side or sides of flues, so that the soot or dust can be removed which
may have accumulated at the bottom of flue amongst the pipes or
tubes by the action of what are known as travelling scrapers or fuel
economisers.
This improved method of procuring licated air I apply to marine steam
boiler furnaces by forming a hollow casing round the funnel or any other
part of the boiler or boilers, and conducting the air entering the hollow
nir tube near the top of the chimney to the furnace or furnaces, and the ;

page_text: .
I also fix metal or other tubes in the chimney of dwelling-houses,
leaving an air space all round the tube, having an outlet coming in con-
nection with the under side of the fire-grate, and extending up the
chimney to near the top. The air enters through a grating fixed in the
3 chimney, heating the air in its descent, which may be conducted into
various rooms on its downward course for warming and ventilation
purposes, or the air may wholly be conducted underneath the fire-
grato.
This my improved Invention is applicable to every description of
furnace, such as the furnaces under dye pans, brewing pans, brick kilns,
or for other purposes where a fire and chimney is erected. At some of
the large factories where a number of steam boilers are worked, the
heated products of combustion on leaving the boiler are made to enter
one flue and pass up the chimney. My object is to distribute the heated
products over a larger area of fluo until it reaches the chimney bottom;
this enables me to procure a large heating surface for obtaining heated
air.
This improved method or methods of obtaining and applying heated
air to furnaces, raising steam, drying animal and vegetable substances,
and ventilating rooms, and for other purposes is produced at no cost
beyond the first outlay, and the heated air effectually consumes the smoke
in furnaces.
This Invention possesses important advantages for obtaining heated air
from the waste products of combustion by jacketing or erecting a
chimney with an air space of several inches round the same betwixt
the inner and outer casing of the chimney, which chimney may be
crected with cross air tubes, so that the air on entering through small
openings at the sides of the chimney pass backwards and forwards
through the air tubes and passages until it reaches the elbow tubes at
the bottom of the chimney, when it enters the air box or chambers of
the longitudinal section, shewn in Drawings connected with the chimney,
containing a number of metal tubes, so that the air is caused to travel
in a scrpentine form through the air tubes or passages from one air box
or chamber to another, heating the air on its passage, which may be
conducted to the ash-pit of the furnace, or the heated air may be drawn
and forced from the air tube formed like a letter D containing a hollow
air space, which air may be conveyed to any required place by means of
a fan or blowing engine for heating, ventilating, or for drying animal

page_text: a serpentine (urection through the tubes marked E, E, E. The nue at
the end of the boiler I mark with F, and letter G shows the end of
steam boiler. The small arrows represent the passage of the products of
combustion from the boiler amongst the tubes, and on its way up the
chimney.
Figure 2 is a transverse section of the longitudinal section connected
to Figure 1, shewing the air box or chambers C, C, with the tubes E, E,
and the metal framework firmly secured by means of bolts, nuts, and
screws marked H, H.
Figure 3 is a plan shewing the position of the tubes E, E, E, as they
stand at the end of the furnace or boiler.
Figure 4 is a longitudinal section as the one connected to Figure 1,
with this exception, the air passages of the chimney are disconnected,
and instead of air being drawn the air chambers and tubes by the
furnace it will require air or liquids to be forced through the valve I
into the chambers C, C, C, C, and is carried in a serpentine manner
through the tubes until the air or liquid reaches the outlet valve K, and
is the conducted to any required place or use. The arrows shew the
direction of the products of combustion amongst the tubes E, E, on tho
way to the chimney when properly fixed.
Figure 5 is a transverse section of Figure 4, shewing a greater strength
of chambers marked C, C, than that which is shown in Figure 2, for the
purpose of maintaining a greater pressure.
Having, thus described the arrangement and working of my Invention,
and the manner in which the same is or may be used or carried into
effect, what I consider to be novel and original and therefore claim as
the Invention secured to me is,―
First. The construction of a chimney containing a metal or other
jacketed air space, with cross tubes forming air passages, having air
openings in the chimney connected to the jacketed air spaces, with a
jacketed elbow tube at the bottom of the chimney, which is connected to
air boxes or chambers, and connected to pipes or tubes passing from one
air box or chamber to the other, causing the air to pass backwards and
forwards to be heated by the products of combustion from the furnace,
and subjecting the air moving backwards and forwards from the chimney
to the furnace through the air tubes or passages to a progressively

page_text: increasing temperature of the air or fluids for heating, drying, ventilating,
and other purposes, while the waste products of combustion move from
the furnace in amongst the tubes on their way to the chimney in a
continuous current, which products of combustion are subjected to a
constantly decreasing temperature of the incoming currents of the air,
liquids, or fluids.
Second. The combination and construction of a jacketed telescopical
steam ship's funnel for the ventilation of the ship's cabins, holds, bilges,
and other parts of the ship which it is desirable to ventilate in order to
preserve the health of the passengers and crew, by connecting air
passages with the jacketed funnel to every part of the ship, or the
jacketed funnel may be connected with tubes leading to the ash-pit of
the furnace.
•
Third. The construction of an hollow jacketed air tube in the form of
a letter D, to conduct the heated air on its passage to the furnace,
while the heated products of combustion pass up the inside of the tube,
keeping the air hot, which hollow pipes or tubes are connected by means
of bolts and nuts, suitable doors or openings being left for access in order
to keep the tubes clean and for repairs.
In witness whereof, I, the said George Rydill, have hereunto
set my hand and seal, this Twenty-fourth day of June, in the year
of our Lord One thousand eight hundred and seventy-three.