IMPROVEMENTS IN THE MANUFACTURE OF LIME AND CEMENT, OR COMPOSITION
Year: 1840

page_text: TO ALL TO WHOM THESE. RESENTS SHALL COME, 1, CHARLES
SMITH, of Exeter, in the County of Devon, Builder, send greeting.
WHEREAS Her present most Excelle t Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the Twenty-seventh day of August, in the fourth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Charles Smith, Her especial licence, full power, sole privilege and
authority, that I, the said Charles Smith, my exors, adiñors, and assigns, or
such others, as I, the said Charles Smith, my exors, adûiors, or assigns, should
at any time agree with, and no others, from time to time and at all times
during the term of years therein expressed, should and lawfully might make,..
use, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, my Invention of "IMPROVEMENTS IN THE MANUFACTURE OF LIME
AND CEMENT, OR COMPOSITION;" in which said Letters Patent is contained a
proviso that I, the said Charles Smith, shall cause a particular description of
the nature of my said Invention, and in what manner the same is to be
performed, to be inrolled in Her said Majesty's High Court of Chancery
within six calendar months next and immediately after the date of the said
in part recited Letters Patent, as in and by the same, reference being there-
unto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Charles Smith, do hereby declare that the nature of my said Invention, and
the manner in which the same is to. be performed, are fully described and

page_text: the Drawings hereunto annexed, and to the figures and letters marked thereon
(that is to say)—
My Invention relates,-
First, to a mode of calcining lime, or cements, or compositions for such like
purposes, by having the kilns so formed that the charge in the upper part of
a kiln shall be calcining whilst the charge in the lower part thereof shall
be cooling, and in cooling the heat and.vapours therefrom shall pass to the
charge in the upper part..
Secondly, my Invention relates to a mode of calcining lime and cements, or
other compositions for such purposes, in ovens, and in such manner that the
calcined products are drawn into a close chamber to cool before being drawn
into the atmosphere, and the carrying-of the gases or vapours so as to apply
them to useful purposes.
Thirdly, my Invention relates to employing the heat which passes away
from lime kilns to the purpose of the evaporation of fluids.
Fourthly, my Invention relates to a mode of slacking lime by the means of
carbonic acid gas in faisuitable cliamber
...
Fifthly my Invention relates to re-calcining lime which has been. previously
calcined and dry-slacked
c
Sixthly; my Invention relates to a mode of treating lime stone by partially
calcining it in a kiln or oven, to convert it into a sub-carbonate, and, cooling.it,
and then grinding and again calcining itsin ovens, whether, separately or¸.com;
bined with other, matters used in making cenients.o
Seventhly, my Invention relates to a mode of making cement by saturating
sulphate of lime with ammoniated and certain other liquor.
to
Eighthly, my Invention relates to a mode of..combining lime.and' cements
with ground calcareous earths and, stones, Jin substitution or in aid of, silex
and other matters.
Ninthly, my "Invention relates to a mode of combining. lime for use..by
applying soap.
Tenthly, my Invention. relates to a mode, of combining water,, lime, and oil,
with or without other. niatters, so as to form. a cement.
**
Eleventhly, my Invention relates to a composition and a formation of tiles
or slabs to-supersede laths and other purposes.
And, lastly, my Invention relates to: a mode of charlening, articles, made of
lime or cement, vand calcarious stone or earth; &c., by placing them in a
chamber' with carbonic acid. And in order to give the best: information, in
my power, I will proceed to describe the processes as pursued. by me...

page_text: .
DESCRIPTION. OF, THE DRAWINGS.
Plan No. 1 represents the section of a kiln, suitably constructed for carry-
ing out the first part of my Invention; and it will be seen that the necessary
flame and heat is supplied through the flues a, a, consequently the kiln-will
be: working to calcine the charge which is above the flues a, a, whether?-the
flame and heat be derived from coke or other ovens or furnaces, or from fire-
places or! furnaces constructed with the kiln, and simply used for applying the
requisite heat to the kiln; but I prefer to use the otherwise waste heat of the
process of making coke or of soda works, or in fact any process where much
heat is now wasted. The construction of lime kilns and the materials used
for that purpose being well understood, it will not be necessary for me to enter
into a particular description thereof, this part of my Invention relating to the
part or parts of the furnace at which the heat and flame from suitable fire-
places or furnaces shall be applied to the charge in kilns; and it will be seen
that in place of such heat and flame being, applied at the lowest part of
the kiln A, the heat and flame are applied at a considerable height up, and
in such manner that the charge below, may cool before being drawn into the
atmosphere, and by which the heat and vapours evolved from the charge in
cooling will pass up amongst the charge in the upper part of the kiln, by
which process of calcining lime and cements, or compositions for such pur-
poses, the product will be better, and obtained at; a less expenditure of fuel,
and by this process it is not necessary to charge-coke or fuel into the kiln
with the limestone or other matter to be calcined therein, unless it be desired
to quicken the process. In- commencing to work with a kiln, constructed as
above explained, a quantity of wood,, or bushes, or shavings, are placed at the
bottom to facilitate the kindling of the coke or fuel, which is to be. charged
into the kiln in the first instance, and until that portion of the charge which is
below the flues a, a, is properly. calcined, the door 6 is to be sufficiently open
to admit the atmosphere. to keep up ignition of the fuel; but when, once
the kiln is at work, and the calcining is conducted by heat, through the 'flues
or openings a, a, the door bis to be kept closed and.luted with clay, excepting
when opened to remove some portion of the charge, and such removing por
tions of the charge I geneally perform, about every six hours, or a shorter.cor
longer period, according to the materials under operation. "By this means, 'it.
will be evident that as parts of the charge are, drawn from below, that which
is above will descend and allow of further quantities to be charged into the
kiln. D is a coke oven, the waste heat of which passes into the kiln Arat one
of the flues a. This oven D also heats the oven G, which is above it, and

page_text: heat is also communicated from the oven D. to the oven F which is below it.
These ovens are for the operation of calcining, so as, if thought proper, their
contents can be discharged through an aperture in the floor of "the ovens and
cooled without coming in contact with external air, such apertures being
closed during calcination. These apertures empty themselves into the arched
vault C, shewn at H, H, Plan 2. The ovens F and G discharge the volatile
gas or vapours from the materials in them into receivers or condensers, or other-
wise, as shewn in the Drawings at I, I, (Plan 1,) and J; which is lined with
lead or otherwise, being closed at the top with a safety valve, and surrounded with
a supply of cold water. The oven F is charged and discharged at the door
shewn at K, (Plan No. 2,) which door during the operation is closed.and
luted, and through which door a proper rake can be introduced by the work-
man in order to stir the materials under operation. The oven G is closed in
Hike manner, and the rake is applied in the same way; but this oven is
charged through the aperture L in the arch or crown of the oven from a small
waggon L, (Plan 1,) moved on a railway, a trap being opened in the bottom of
the waggon, and at the top of the oven the contents fall through the aperture
into the oven and are distributed over the floor by a rake, and the waggon
is removed and the aperture closed and luted tight during the operation.
These ovens act as retorts, or the ovens can be heated by separate fires in
place of the coke oven, as shewn at M, (Plan 1,) which are ovens such as can
be used at the gas or soda works, the waste heat of which I intend occa-
sionally to apply to my manufactory in lieu of or combined with the waste
heat of coke ovens, and can be applied to my purpose or process of calcination
as before described; and these ovens are so constructed as to have a bottom,
side, and top heat, which is performed by flues, as shewn in the Drawings.
These ovens can be built with fire blocks, grooved and tongued together at
the joints, as shewn, or with fire bricks; and the upper oven, which will be
of a less heat, can be constructed with good common fire bricks, and the
bottom and sides clipped firmly together with a wrought or cast iron grating,
as shewn at N, the bars of which are not to be less than three inches wide
and three quarters of an inch thick, and placed one foot from middle to
middle, so as to take a foot square fire tile, or a covering of fire stone; and the
same kind of grating I apply to the oven over the coke ovens, as shewn at
N, Letter G. The operations are carried on in these ovens in like manner as
above described, and they are charged and discharged in the same manner,
and their volatile gaseous vapours can be condensed in the same manner, or
conveyed and applied in various other ways at pleasure. I would remark,
that I do not claim to heat ovens for calcining purposes by any particular

page_text: means, neither do I claim the calcining of lime or cements, or such like
compositions, in ovens, this second part of my Invention simply relating to
connecting ovens in which cements are calcined, with a suitable closed,
chamber into which the calcined products are drawn to cool before being,
drawn into contact with the atmosphere.
I will now describe the third part of my Invention. In calcining lime in,
kilns it is well known that much heat passes into the atmosphere and is.
wasted; now, the object of this part of the Invention is to employ such waste
heat to the purposes of evaporating fluids; and to carry out this part of my.
Invention, I apply a boiler, as shewn at O, which is so made as to run over or
away from the upper part of the kiln on a railway. P are strong iron doors
which are to open to throw in the materials. Q is a flue to convey the heat.
and gaseous vapour from the materials in the kiln to the chimney R, and to.
the room S, the smoke from the flues a being consumed in passing through
the hot material in the kiln. T is a boiler or evaporating pan, which is heated
by the flue Qwith the waste heat from the kiln A, and can be of a much
greater length than here shewn, and can be opened or closed at pleasure
by the cover V. I would remark, that the construction of boilers or pans used
may be varied according to the purpose to which they are to be employed, and.
as, is well understood, such boilers or pans forming no part of my Invention.
In carrying out the fourth part of my Invention, I take any quantity of
lime which has been calcined as before described (which I prefer), or by any
other method, and I allow it to slack in a dry covered place or chamber, as
shewn at X, and there allow it to slack, which it will do in a superior way, by
imbibing the carbonic acid from the flue which falls through the aperture (1),.
Plan 1, which is opened and closed at pleasure by the trap door (2) by a rope,
or chain passed over pullies to the outside of the building. The entrance door
to the room S is to be closed air-tight during the operation, and the trap door
(2) to remain down, and the valve in the chimney at (3), Plan 1, closed; but
a short time before a person can enter the room S, the valve (3) and entrance
door must be opened, and the trap door (2) drawn up close, so that the
gaseous vapour in the room S may disperse and escape. I then take the
slacked or sub-carbonate of lime and use the same, or I place it in the waggon
and pass it through the aperture into the oven, which is to be distributed.over.
the bottom by the rake to about four inches thick; and when the carbonic acid
imbibed is driven off through the pipe I, Plan 1, which will be in about four
hours, it is then to be passed through the aperture in the floor H, (Plan 2,)
into the vault, and there allowed to cool, and then taken and ground and finely
sifted, and put into tight casks and kept for use, or it can be immediately.

page_text: applied to any kind of work. The above described process gives to the lime a
setting quality. without the risk of what the workmen call blisters. I occa-
sionally give to the lime a greater solidifying quality when to be used for
external works. For this purpose, when I take-the--lime from -the room S,
(Plan 1,) before the second calcination; I. add-to cach bushel one peck or
thereabout of fine ground forge clinkers, or fine ground-burnt aluminous.earthy
matter; or the scoria or slag from 'smelting-furnaces, and mix it well together
and then place it in one of the ovens, as before described. This quality is also
given to 'the 'compound carbonate of lime when broken into small fragments,
and at once wholly calcined and cooled in this way, but then the process. is
longer in action. It must remain in the oven for about twelve hours; and this:
process is expedited by a small current of vapour emitted through à pipe andr
valve at pleasure and all natural cements, or artificial mixtures of calcarious,
magnesian and other earths,' oxydes, or salts, is much improved when calcined;
by either of the before-mentioned processes over the present-system of
manufacture. Highly hydraulic or compound limes in general, when calcined:
and cooled in covered kilns, as described in Plan No. 1 in the kiln A, will
have this property, and can be instantly ground and finely sifted for use
without the second process above described being applied; or. I break:
calcarious stone into fragments of not exceeding one-pound weight or there-
abouts, and I place it in the waggon L'and pass-it into the oven G, sufficient
to cover the bottom five or six inches thick, and I suffer it to remain about
half the time it would take to calcine, about six hours, so as to convert it into
a sub-carbonate. I then discharge it through the aperture H into the vault C
to cool; I then take it out and grind it to powder, and it can be used in this
state; and, if required for external work, I occasionally. mix to each bushel of
it one peck or thereabouts of the fine-ground forge clinkers, or fine-ground
burnt aluminous earthy matter or scoria, or slag from sinelting furnaces, as
before described, and again place it in the oven for about six hours, and again
discharge it into the vault C, (Plan 2,) to cool, when it will be fit for use; or
in lieu of grinding, before the second calcination, I place it in kiln. A, and
secondly calcine it there for about the same time, and when cool I grind. and
sift it for use. This process also gives a setting quality; and the. first as well
as the second part of this process I carry on in the kiln A, by passing the
materials through the kiln in one half the time it takes to calcine, and allow it
to cool, and again place it in the kiln' for about the same time, and cool and
grind the same. The above process I prefer for the purest kinds of the
carbonate of lime; and I may here mention that different .ingredients, suitable
for making cements, can be incorporated in the sub-carbonate before the

page_text: second calcination.I form a cement.:fromi sulphate of lime or gypsum and
such like calcarious earths, or any moulds or things, that have been formed of
plaster of Paris of commerce, of which I take any quantity and grind it to a
power, or break it into small pieces so that it will pass through. a.šieve of
not more than three,quarters of an inch mesh: I then place it in 'the oven:G;
Plan 1 until it covers the floor about three finches; thick.: The oven is then to:
be closed and the charge remain until the water of:.chrystallization; &c., is
driven off, which will be in about four hours. A person attending on this part:
of the process will soon be acquainted with it, as these, ovens are nearly always:
at the same temperature, that of a red heat; visible: by daylight, so that when!
the time is known which it takes in this part of the process it is only to repeat
it for a similar material. The gaseous vapour, arising from these materials:
during this process is carried; off through the pipes I, (Plan. 1) into- the:
condenser. When the charge in tho oven is finished,.it is raked, into thė;
aperture, H; (Plan 2,) which conveys it into the vault C, (Plan 2,) and'is there!
allowed to cool. The aperture is immediately closed, and another charge
placed in the oven G. The charge in the vault C being cool,.. I open the door,
Figure 4 (Plan 2,) and take it out, and place it in a cistern or tank, and, pouri
in a sufficiency to cover it' of, the purified liquor prepared from the ammoniated
fluid formed in the manufacture of coal gas commonly called gas water, or of
purified human urine, or purified liquors' resulting from the distillation of
bones or other animal matters, and' those.liquors will be: fit for the the purpose.
after any tarry or extraneous 'matter has been carefully separated from them,
either by lixivation in any convenient way, or evaporated by this.or a similar
boiler on the top of the kiln. The boiler inust be connected with a receiver,
which should be kept cool. This-boiler answers, the purpose well, as the heat
is required somewhat below, boiling. The liquor thus obtained will answer.
the purpose well of itself, as this: process converts the sulphate of:lime.
into a sub-carbonate, and the carbonated liquors into la 'sulphate; and when
the. sub-carbonate is,a second, time calcined, as: hereafter, described, it, has a
hard setting quality; or a greater chrystallizing power can be given to it by
dissolving in each gallon of the liquors a quarter of a pound of either of the
alkaline or earthy salts, or aquarter of a pint of the, mineral acids might be
added, but generally prefer the purified liquor alone, although I do, not
confine; inyself thereto... After it has absorbed as much as possible' of the
solution, which will in general be in forty-eight hours, the materials thus
saturated;are-then to be removed from the cistern or tank, and placed in the
oven F,(Plan 1) or pan T, (Plan 1,) and then dried; or it can be dried.iby
any other means; but by the gradual uniform beat produced by this treatment,

page_text: the greatest part of the volatile salts contained in the liquors will pass off into
the condenser through pipe I, or from the pan into a cool receiver, and the
charge thus dried is then to be placed in the waggon L, and add thereto about
one fifth or thereabouts of dry powdered lime, and if thought proper about the
same quantity of calcined magnisia, which is to be passed through the
aperture into the oven, as described in the first part of this process, and to be
distributed over the oven's.bottom in the same manner, and to remain about the
same time, and to be discharged through the aperture of the floor into the vault;
and when cooled the burnt materials are to be removed and reduced to powder
by grinding between horizontal stones or by any other means usually employed
for grinding such dry substances, and then if required sifted fit for use. The
remaining part of volatile salt left is set free by the fifth part of lime being
added, and is carried off through the pipe I into the condenser J. The composi
tion thus formed in the condenser from the volatile part of this process is then
removed into suitable vessels, and, being brought in contact with acids, the
compound salts are formed in the usual way, which is well understood, but
of superior quality, and the nuisance such operations in general create will
be obviated. In combining lime and cements for use I take Portland,
purbeck, marble, or any hard calcarious or such like stone, and grind or
pulverize them by stamping mills, rollers, or edge stones, or such like
machinery, or by any power, or by manual labour, and sift the same to
different degrees of fineness, according to the work intended; and this I mix
with any kind of lime, or natural or artificial calcarious cements, for all
kinds of work, whether manufactured by my processes herein described
(which I prefer), or any other. The guage of mixing will greatly depend
on the work, but two of ground stone to one of lime or cement will be
generally the average quantity required, and I occasionally grind forge clinkers
or burnt aluminous earthy matter, or the scoria or the slag of smelting
furnaces, or any kind of articles or things which have been formed of
aluminous earths, or admixtures thereof, after they have been well burnt,
but not glazed, or of any broken fragments of the same, ground into a powder,
and mix about one peck of it to four of ground stone, which gives the
composition a quicker solidifying quality, and a small quantity of sharp sand
might be added and mixed with the above, but the calcarious kinds are
generally to be preferred, and acids, or alkalies or earthy salts may be mixed
in small proportions with the above, to assist in crystallization. Care must
be taken that their use must not be carried to excess. I most prefer for
this purpose the solution of the sulphate of potash or alum, or the mother
water of the alum works, and I mix it together before or at the time of its
.

page_text: use; and I can manufacture any kinds of solids or surfaces, plain or orna-
mental, attached or detached to buildings, and all such like purposes in the
above compositions, and I expedite the solidifying qualities of such articles.
as are moveable by submitting them to the following process: -After they
are cast or formed by any other means, and are become sufficiently hard
to be removed, I place them, if required, in the room S, (Plan 1,) shewn at W,
and I occasionally wet them with lime water, or a solution of the sulphate.
of potash or alum water, or the mother water of alum works, and this I can
apply to all kinds of surfaces and articles, whether they pass through that:
process or not. The lime water I form thus: three pounds of lime in five:
gallons of water, keeping it stirred while slacking, and then allowing it to
precipitate until the water for use is become clear. The solution of the
sulphate of potash I form by dissolving a quarter of a pound of the potash of
commerce in one gallon of water, and pour into it sulphuric or other acids
until effervescence ceases. The alum' water I form by dissolving half a pound
of alum of commerce in one gallon of water. I prefer the lime water, as:
the carbonic acid obtained from the flue, &c. acts upon it more rapidly, and
tends to recompose the articles into a stoney hardness, which it will do in a.
short time, varying according to the thickness of the articles; but if exposed
to the open air without going through the above process, the composition will.
harden more slowly. And I manufacture a cement or composition whereby:
any uniformity or admixture of colors can be given to it, and all marbles
and other stones can be imitated, or figures or landsȧpes can be described, in
the following manner :-I take fine sifted sand, or ground stone, but I prefer:
the hard calcarious kinds, and more particularly marble or ground gypsum,:
from their perfect whiteness, which renders them more susceptible of a variety:
of colors or tints being combined with them; I take two parts, say, of
ground marble, and I mix it with one part of fine slacked or ground lime,
with the least quantity of water possible, and this I do two or three days.
previous to using the same, but I temper it once or twice a day without any
addition of water, by a beater, or similar useful tool; I next take one pound
of soap, and dissolve it over a slow fire in about six quarts of water.
I prefer
the best kinds of soap for the purpose, and I occasionally add about two
ounces of glue or other glutinous matter to the same, by which means the
5 cement is rendered more tenacious. I take the composition of lime and
marble, or other matters, prepared as above, and I add to it the color to
form the tint required for the ground color, and bring it to the consistency
for use by pouring into it the soapy solution, and temper it, and well mix it
together, and apply it to any floated plastering, or other dried surfaces, in the

page_text: manner that stucco is at present done, and I'hand, float, or trowel the surface in
like manner; and if marble' or figures is intended to be represented, I-take fine
slacked lime; and mix it with the soapy solution; and pour it into different
vessels; and apply it to the different tints, and I-mix-it to the 'consistency of
paint, and apply it to the trowelled-surface with brushes, sponges; and tools
used by artists; and marbles can be imitated; or figures described, according
to the taste of the operator, but: care must be taken's not to commence: any:
more at a time than can be finished before it gets too dry; and when the
surface is to remain of one color; the trowelled" surfaces Illayover with a
solution of the proper tint, and when that is done, as well as the.above, I pass
a highly burnished hot metal tool over the surface, which will unite the
whole, and "form a good spolish; which will in general be sufficient, but ican
receive a small additional polish by the process applied to scagliola, which is.
well understood. Such surface, when dry, is impervious to moisture, and of
extreme liardness. Marblexcan bet iinitated.in. this way by finishing the
surface of one luniform color, and then staining it as is customary in staining
marbles; which is also well understood. The tools must be in different forms,t
according to the surfaces: to be passed, over, but flat surfaces I form by similar
tools to those shewn in Plan No. 4, which will give a good idea. .to the.
formation of other tools which must.be' formed with; hollow, flát, or rounded;
surfaces to fit mouldings; &c.
Plan No: 4 (1) is a stove for burning coke, or other fuel; which:I'propose:
for heating the 'tools, which are placed in the sockets, as therein shewn, or
they can be heated in any other way. (2) Plan 4, is ar tool about. the? full:
size; and with the two liandles fitted to it. The one placed in the groove, as
shewn, or screwed into therback, is removed at pleasure and can be made to
fit any number of tools. This handle can have an universal joint, cor..a single
onc, as shewn at (3), which will allow the tools to turn in any direction
required whilst in use. Figure 4. shews the back of the tool, 'with the
mortice for receiving the handle, and (5) shews: a cross section, with the
mortice also for receiving the handle. These tools must not be "heated to
more than a moderate black hent, which will be found sufficient for the
purpose. A little "plaister of Paris,can be added to the composition when'
it is required to set quickly for internal work; or for casting with the same;
but: for. internal or external 'work I use the cement prepared of my process
from sulphate of lime,, or gypsum, or such like calcarious matter, or calcined
magnesia, for the same purpose above described; or I form this composition.
with it without the admixture of lime, but then it must be mixed in small
quantities as it is used, and enough of the different tints must be mixed
:

page_text: in the soapy solution to, compléte one piece of work intended to be of;, one
uniformity of..color or tint. And I manufacture a cement or composition,.
which I use as a 'plaster or stucco or scagliola; or Irun or form mouldings,
and cast,any kind of ornaments or figures, in the same, and any color or tint,
can be mixed with it, at pleasure, and, surfaces can be finished to resemble;
freestone, 'or trowelled smooth, as is practised on smooth stucco, and, if.thought;
proper, when dry it can be. polished in the same way as scagliola; or I lay;
it over with my composition, mixed with the soapy polish, and, I polish it as I,
have, before described. First, I take clean, water, any number of gallons;.
and I add to it is: much fresh-burnt, lime as will, when slack,,,bring it to,
a semi-fluid consistency; but when, the lime is about .hálf, 'slacked I add to it
as many quarts of oil as there are gallons of water. previously added; any,
kind of oils: will. do, either raw or boiled in .the usual way, but, I prefer the.
vegetable oils for the purpose. I stir this, well together, until the whole is
properly mixed, I then strain. it through a fine. sieve, and, when cool, it is fit;
for use. I then incorporate with. it; if' thought proper; two parts, or there-,
abouts, of the ground stone or marble before described; which I 'prefer, or;
with other hard sand, or mineral or metallic oxides or, carthy,matter fit for
the purpose may be used, and..when well..mixed and tempered I apply it
in the same manner as plastering or stucco is performed, which is well;
understood; .or I finish it as before described; and when I require it to. set
quickly for any, kind of..work, I mix it at discretion with plaster of Paris' of:
comnierce, manufactured in the usual way, or with my composition .prepared;
from the sulphate of lime or gypsum, orisuch like calcarious matter or calcined;
magnesia, and with or without any other mixture;. or I can mix it with the:
sulphate of lime manufactured in combination with; any of the mineral, earthy, or
alkaline salts: or acids, but I prefer: the plaster of Paris of. commerce pepared in
the usual way or the sulphate of lime. after. being operated upon by my process,
but I do not confine myself thereto, as a variety of mixtures can be applied to,
lime when mixed as before described. A composition. mixed.in this way does'
not, when it becomes. dry, absorb moisture, and can be used externally as well.
as for internal work, and can be applied for coating or as the finishing coat on:
any walls, buildings, cement,. or composition, and will be found much to.
improve and dispatch the work intended to be painted..
. It is the present practise.with builders to nail laths against joists, partitions,,
&c.,.to receive the different contsiof plastering in the internal and external parts
of buildings; now, my, Invention relates to preparing composition or cement!
tiles to supersede, laths; and I'make such tiles of the following composition:
I take about three parts of good caluminous carthy matter, and I mix it, with

page_text: about one part of ground clinkers, or the scoria or the slag from smelting fur-
naces, and when properly tempered they are made, driel, and burnt in a similar
manner as at present applied to the manufacture of roofing tiles and such like
articles, as is well understood; and these tiles or slabs can be made to any form
and different thicknesses according to the work intended for their application;
and I make them rough on one side in order that the compositions applied might
adhere firmly in a similar manner, or to answer the same purpose of roughing
or scratching, applied by plasterers to what they term their pricking-up coat.
And these tiles or slabs serve the double purpose of laths and the pricking-up
or first coat, and will greatly facilitate the finishing of buildings, as the
workman can apply his floating or laying coat of mortar or any building
cement or composition, and finish without the least delay; and the economy
in adopting this method will be seen in calculating the expence of the lath and
pricking-up coat, and their less liability to destruction by time or fire. The
application will tend much towards rendering buildings fireproof. And in order
to shew some of the forms which I adopt, and that their application may be
understood, which will give an idea that almost an infinite number of shapes and
sizes can be given. And I will here mention that I do not confine myself to
any particular shape, size, or form, my Invention relating to any form, and
their application.
Plan No. 5. (1) shews tiles or slabs which reach from the middle to the
middle of joists or studs, &c. in one piece, and are made about half an inch
thick at each end, and about three quarters of an inch thick in the middle,
the extra thickness being on the upper or back side to give them additional
strength, and their ends can be straight or notched, as shewn, and are fastened
to the joists or studs, &c. with stout-headed nails or screws through holes
formed in the tiles or slabs. The above thickness will be found sufficient
where the materials used in their formation and manufacture are of the best
quality for the purpose, or an uniform thickness of five eighths of an inch will
be found to answer the purpose well. The roughing or scratching can be
formed in the moulding by a notched wood or metal strike or rule passed over
their surface, or otherwise; and these tiles or slabs can, if required, be placed
or fixed against screeds formed in cements about three inches wide, in lieu of
battens, &c. against walls, &c.; and Figure 2 is another way of performing
when tiles or slabs are formed in shorter lengths. These are fixed so as to
project equally on each side of the joists, and the one in the middle to be
rabitted, so as when jointed in strong cement their under surface becomes
even with those on each side which are fastened to the joists, and a strip or
narrow piece of wood is nailed on their upper sides against the joist to

page_text: keep them in place, or a filletting of cement can be used for that purpose.
And these tiles or slabs can be applied without nails or screws when the
joists are of iron, with a flange formed on their under side, as shewn at
Figure 3. These tiles or slabs are rabitted, as shewn, so as when they are
bedded at each end in strong cement their under surface becomes level or
even with the joists, &c., and can be fastened down, as shewn, or by a filleting
of cement, as before described. Holes, in lieu of roughing or scratching or in
union with it, can be adopted to form the key for the compositions applied to
them, and a variety of different thicknesses can be given them according to
the distances between the bearings, so as to obtain the strength required;
and these tiles or slabs can, if required, be rabitted and jointed together in a
variety of ways. Those above explained only refer to some of the simple forms
I adopt.
Having thus described the nature of my Invention, I would have it under-
stood that what I claim is,-
First, the mode of calcining lime, or cements, or compositions, by means of
kilns so formed that the charge in the upper part shall be calcining whilst
the lower part of the charge is cooling, and in cooling the heat therefrom
passes up amongst the upper part of the charge of the kiln.
:
Secondly, I claim the mode of calcining: lime and cements in retorts or
ovens when in connection with a closed chamber, wherein the matters can
be cooled before being brought into the atmosphere, and also the carrying
off the gases or vapours, so as to apply them to a variety of useful purposes. }
Thirdly, I claim the application of the heat of lime kilns to the purposes of
evaporating fluids in suitable boilers or pans, as above described.
Fourthly, I claim the mode of slacking lime in chambers with carbonic acid,
as above described.
Fifthly, I claim the mode of manufaturing lime by re-calcining it after dry-
slacking.
Sixthly, I claim the mode of manufacturing lime by partially calcining lime-
stone in a kiln, in order to convert it to sub-carbonate, and after cooling and
grinding again, to calcine it, whether separate or combined with other matters
for making cements.
Seventhly, I claim the mode of making cement by saturating sulphate of
lime with ammoniated liquor or other matters, as above described.
Eighthly, I claim the combining lime and cements with ground calcarious
earths or stones, in substitution or in aid of silex or other matter.
Ninthly, I claim the mode of combining lime for use by applying soap with

page_text: or without glutinous matter, and also the method or process of using hot tool's
for finishing and polishing cemented surfaces.
Tenthly, I claim the mode of preparing cement from lime by means of oil
and water, with or without other materials; as above described.
Eleventhly, I claim the combining aluminous earths and ground clinkers,
or slag or scoria from the smelting furnace, and: the forming and burning
of tiles thereof. And I also claim the forming of tiles or burned rough
surfaces to be used in substitution of laths to receive cemented: surfaces; as
above described.
And lastly, I claim the mode of treating articles made of lime or cement,
and calcarious stone or earth, by placing them in chambers with carbonic acid,
as above described.
In witness whereof, I, the said Charles Smith, have hereunto set my
hand and seal, this Twenty-seventh day of February, in the
our Lord One thousand eight hundred and forty-one.
year of
CHARLES (L.S.) SMITH.
AND BE IT REMEMBERED, that on the Twenty-seventh day of February,
in the year of our Lord 1841, the aforesaid Charles Smith came before our
said Lady the Queen in Hér Chancery, and acknowledged the Specification
aforesaid, and all and every thing therein contained and specified, in form
above written. And also the Spécification aforesaid was stamped according
to the tenor of the Statute made for that purpose...
Inrolled the Twenty-seventh day of February, in the year of our Lord
One thousand eight hundred and forty-one.