AN IMPROVED CONSTRUCTION AND MANUFACTURE OF RETORTS, CRUCIBLES, GLASS-HOUSE POTS, AND OTHER SIMILAR VESSELS, AND IN THE MEANS AND APPARATUS EMPLOYED THEREIN
Year: 1864

page_text: LETTERS PATENT to James Gillespie, of Garnkirk, in the County of
Lanark, North Britain, Manager, Garnkirk Fire-clay Company, for the
Invention of "AN IMPROVED CONSTRUCTION AND MANUFACTURE OF RETORTS,
CRUCIBLES, GLASS-HOUSE POTS, AND OTHER SIMILAR VESSELS, AND IN THE
MEANS AND APPARATUS EMPLOYED THEREIN."
Sealed the 19th June 1865, and dated the 22nd December 1864.
PROVISIONAL SPECIFICATION left by the said James Gillespie at the
Office of the Commissioners of Patents, with his Petition, on the
22nd December 1864:
I, JAMES GILLESPIE, of Garnkirk, in the County of Lanark, North
Britain, Manager, Garnkirk Fire-clay Company, do hereby declare the nature
of the said Invention of " AN IMPROVED CONSTRUCTION AND MANUFACTURE OF
RETORTS, CRUCIBLES, GLASS-HOUSE POTS, AND OTHER SIMILAR VESSELS, AND IN THE
MEANS AND APPARATUS EMPLOYED THEREIN," to be as follows, that is to say :-
This Invention consists in and relates to new and improved modes or
methods of constructing or manufacturing retorts, crucibles, glass-house pots,
and other generally similar vessels subject to great and sudden variations of
temperature in their use, and having the heat usually applied in a more or
less irregular manner to their outer surfaces, whereby such vessels are:
rendered more durable and less liable to crack or fracture than as heretofore.
constructed, and includes several minor details, means, and apparatus for
effecting the same.

page_text: The principal and essential improvement of this Invention consists in form-
ing or constructing the whole or the greater part of the "walls," sides, ends,
or bodies of retorts, crucibles, glass-house pots, and other generally similar
vessels of two or more layers or thicknesses of whatever material they may be
made with, or having thin or slight divisions, spaces, or "partings" between
the contiguous or adjacent surfaces of such layers or thicknesses.
Many good and practical ways or methods of working out the above named
main feature of this Invention will at once occur to the makers of such vessels,
all of course varying according to the nature, the size, and form of which the
vessels are to be constructed. It will therefore be sufficient to specify a few
of the improved modifications of this Invention, and the means or apparatus
for working it out as more particularly suitable for the construction or manu-
facture of retorts, crucibles, glass-house pots, and other generally similar
vessels as are most generally in use and made from fire-clay and other plastic
materials, and which usually require to be kiln-dried or otherwise baked to
complete them.
Thus then one modification consists in forming or building the retort or
other vessel out of the fire-clay or other plastic material in the usual manner,
only making the first layer which forms the inner shell of the vessel thinner
at those parts where the "wall" is to be made of two or more layers or
thicknesses, but conjointly with those parts desired to be as usual of one great
thickness, the parts most liable to the injurious action of the flames or heat
being those usually preferred to be formed in several layers; then to form the
parting or division one or more thicknesses of paper, cloth, felt, or other
similar thin substance destructible by moderate heat is rolled round the out-
side of the thin part of the first layer of clay, after which the second layer is
formed or built over this, and should a third be desired a second "parting"
is formed between the second and third layers in the same way as that
between the first and second, and so on for as many courses or layers as are
required. These divisions or "partings" may either extend out to the end of
the vessel or not as desired, and when they do not, all the several layers of
clay join and form one thick layer from the outside to the inside surface at
one or both ends of the vessel. However, when desired, the close end
bottom of such vessels may also be constructed on this improved system
building or forming it in layers, and placing thin plies of paper or other similar
substances between them. Instead of forming the "partings" between the
layers of clay as described in the former modification, a thin coat or thickness
of pulpy or liquid substance may be brushed, "swaped," or poured on each
thickness of clay as it is formed before the next layer is placed over it, such

page_text: substance being composed of, by preference, the various vegetable and other
matters used for making the coarser kinds of paper and felt or other substance
or material which would partially burn out in the baking, or at least form a
distinct "parting" which would effectually prevent the adhesion of the layers
and admit of their expansion at different ratios as the heat penetrates them,
and in consequence prevent any crack or fracture caused to an outer layer by
undue or sudden heating from penetrating further than the next "parting,"
thus lessening the chances of breakage to the inner course or shell, and at
the same time distributing the heat more equally round the whole vessel
before reaching it.
Another modification for forming these "partings" between the layers,
particularly of parallel vessels of various sections, such as round, oval, poly-
gonal or D shaped retorts, is to place between the layers as they are being built
a thin deep or broad metal ring or band of a shape and size corresponding
to the block or core piece for forming the interior of the vessel, but leaving
the proper thickness of clay between it and the ring, and as this and the out-
side layer is formed, the ring is raised from time to time by itself in the same
way as the core piece is at present, or both may be attached and raised
or drawn out of the mould together. By this means a thin hollow space
would be left all round between the layers, which might in some cases be
filled up with any fine dust or ash which would not solidify or adhere to the
surface of the clay under the action of heat, but keep the layers quite separate
so as to allow of their individual expansion. In some cases the outer layers
are pierced or formed with a few small holes laterally so as to admit of the
escape of any steam or gases which might be injuriously confined between
the layors and engendered in the baking.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said James Gillespie in the Great Seal Patent Office on the
21st June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
GILLESPIE, of Garnkirk, Lanarkshire, Manager, Garnkirk Fire-clay Company,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of December, in the year of our
Lord One thousand eight hundred and sixty-four, in the twenty-eighth year
of Her reign, did, for Herself, Her heirs and successors, give and grant

page_text: unto me, the said James Gillespie, Her special licence that I, the said
James Gillespie, my executors, administrators, and assigns, or such others
as I, the said James Gillespie, my executors, administrators, and assigns,
should at any time agree with, and no others, from time to time and at
all times thereafter during the term therein expressed, should and lawfully
might make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "AN IMPROVED CONSTRUCTION AND MANUFACTURE OF RETORTS, CRUCIBLES,
GLASS-HOUSE POTS, AND OTHER SIMILAR VESSELS, AND IN THE MEANS AND APPARATUS
EMPLOYED THEREIN," upon the condition (amongst others) that I, the said James
Gillespie, 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
samo 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 James Gillespie, do hereby declare
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 in writing, reference being had to the accompanying
Drawings and to the letters and figures marked thereon, that is to say :-
My said Invention consists in and relates to new and improved modes or
methods of constructing or manufacturing retorts, crucibles, glass-house pots,
and other generally similar vessels, subject to great and sudden variations of
temperature in their use, and having the heat usually applied in a more or
less irregular manner to their outer surfaces, whereby such vessels are rendered
more durable, and less liable to crack or fracture than as heretofore con-
structed, and includes several minor details, means, and apparatus for effecting
the same.
The principal and essential improvement of my Invention consists in
forming or constructing the whole or the greater part of the "walls," "sides,"
ends, or bodies of retorts, crucibles, glass-house pots, and other generally
similar vessels of two or more layers or thicknesses of whatever material they
may be made with, or having thin or slight divisions, spaces, or "partings,"
between the contiguous or adjacent surfaces of such layers or thicknesses.
Many good and practical ways or methods of working out the above-named
main feature of my Inventiou will at once occur to the makers of such vessels,
'all of course varying according to the nature, the size, and form of which the
° vessels are to be constructed. It will therefore be sufficient to specify a few of

page_text: the improved modifications of my Invention and the means or apparatus for
working it out, as more particularly suitable for the construction or manu-
facture of retorts, crucibles, glass-house pots, and other generally similar
vessels as are most generally in use, and made from fire-clay and other plastic
materials, and which usually require to be kiln-dried or otherwise baked
to complete them. Thus, then, one modification consists in forming or
"building" the retort or other vessel out of the fire-clay or other plastic
material, in the usual manner, only making the first layer which forms the
inner "shell" of the vessel thinner at those parts where the "wall" is to be
made of two or more layers or thicknesses, but conjointly with those parts
desired to be, as usual, of one great thickness, the parts most liable to the
injurious action of the flames or heat being those usually preferred to be
formed in several layers, then to form the "parting," or division, one or more
thicknesses of paper, cloth, felt, or other similar thin substance destructible by
moderate heat are rolled round the outside of the thin part of the first layer
of clay; after which, the second layer is formed or built over this; and
should a third be desired, a second "parting" is formed between the second
and third layers in the same way as that between the first and second, and so
on for as many courses or layers as are required. These divisions or
"partings" may either extend out to the end of the vessel or not, as desired,
and when they do not all the several layers of clay join and form one thick
layer from the outside to the inside surface at one or both ends of the vessel.
However, when desired, the close end or bottom of such vessels may also be
constructed on this improved system by building or forming it in layers and
placing thin plies of paper or other similar substance between them. Instead
of forming the "partings" between the layers of clay, as described in the
former modification, a thin coat or thickness of pulpy or liquid substance may
be brushed, "swaped," or poured on each thickness of clay as it is formed
before the next layer is placed over it, such substance being composed of, by
preference, the various vegetable and other matters used for making the
coarser kinds of paper and felt; or other substance or material which would
partially burn out in the baking, or at least form a distinct "parting," which
would effectually prevent the adhesion of the layers and admit of their expansion
at different ratios, as the heat penetrates them, and in consequence, prevent
any crack or fracture caused to an outer layer by undue or sudden heating from
penetrating further than the next "parting," thus lessening the chances of
breakage to the inner course or "shell," and, at the same time distributing
the heat more equally round the whole vessel before reaching it.
Another modification for forming these "partings" between the layers, par-

page_text: ticularly of parallel vessels of various sections, such as round, oval, polygonal,
or D shaped retorts, is to place between the layers as they are being built
a thin, deep, or broad metal ring or band, of a shape and size corresponding
to the block or core piece for forming the interior of the vessel, but leaving
the proper thickness of clay between it and the ring, and as this and the out-
side layer is formed the ring is raised from time to time by itself, in the same
way as the core piece is at present, or both may be attached and raised, or
drawn out of the "mould " together. By this means a thin hollow space
would be left all round between the layers, which might in some cases be filled
up with any fine dust or ash, which would not solidify or adhere to the surfaces
of the clay under the action of heat, but keep the layers quite separate, so
as to allow of their individual expansion. In some cases the outer layers are
pierced or formed with a few small holes laterally, so as to admit of the escape
of any steam or gas, which might be injuriously engendered and confined in the
baking.
And in order that my said Invention may be properly understood I shall
now proceed to describe the several illustrative Figures upon the Sheet of
explanatory Drawings which I have hereunto appended for the purpose of
showing certain modifications under which my improvements may be judi-
ciously carried out in practice, similar reference letters being employed to
indicate similar or corresponding parts in all the Figures.
Figure 1 is a transverse vertical section of one modification of a D shaped
gas retort, and Figures 2, 3, and 4 are longitudinal vertical sections of
D shaped retorts corresponding to Figure 1, but each showing different modi-
fications of my improvements.
Figures 5, 6, and 7 are transverse views respectively of a cylindrical, cylin-
droidical or oval, and hexagonal retort, each shown half in vertical elevation
and half in vertical section.
Figures 8, 9, and 10 are longitudinal views respectively of a cylindrical,
tubular, and conical retort, each shown also half in vertical elevation and
section, and illustrative of the application of various modifications of my
improvements as applied to retorts.
Figures 11 and 12 are each half vertical elevations and half vertical sections
of crucibles constructed according to and illustrative of two modifications of
my improvements as applied to such vessels, and Figure 18 is a horizontal
section of the same corresponding to Figures 11 and 12.
Figures 14 and 15 are each half vertical elevations and half vertical sections
of glass-house pots constructed in accordance with two modifications of my
improvements.

page_text: ""
"
In these several modifications of my Invention shown in Figures 1 to 14
inclusive as applied to retorts, crucibles, and glass-house pots, the "walls,"
"sides," or
"bodies" of these several vessels are each formed or constructed
of two layers or thicknesses, namely, an inner "shell" or casing A, and an
outer "shell or casing B, throughout their entire circumference, as shown
in Fi
1, 5, 6, 7, and 13, with or having the narrow annular space or
"parting" C, formed between them in such a manner as to prevent the adhesion
of their adjacent surfaces. These double "walls or "shells" A, B, and
division or "parting " C, are also made to extend throughout the greater part
of the length of the body of the vessels, by preference, particularly at the
parts where they are subject to the greatest action of heat in their use, as
shown from a to b in the several Figures 2, 3, 8, 11, and 14, and also in
some cases in a continuous course at and round or across the close end of the
vessels or retorts as shown at A¹, B, and C, in Figures 2, 4, 8, 11, 12, 14,
and 15, the two "walls" A, B, being formed into one great thickness at b,
where the "parting " C is made to end so as to form a solid open "mouth"
piece from 6 to 6' as shown in Figures 2, 3, 8, 11, and 14. Otherwise the
double "walls" A, B, and "parting" C may be made to extend throughout
the whole, or from end to end of the retort or vessel as shown from a¹ to b¹ in
the several Figures 4, 9, 10, 12, and 15, in which modifications the inner and
outer "walls" or "shells" A and B form as it were separate cases or vessels
formed or placed inside each other, having a narrow space or "parting" C
between them.
"
Figure 15 shews a modification of my Invention as applied to a glass-houso
pot, having three "walls or "shells" A, B, and D, each formed upon, or
placed over each other after being formed, with or having the two narrow
spaces C and E between their contiguous or adjacent surfaces.
The important feature and advantage gained in this my improved construc-.
tion or constructions of retorts, crucibles, and glass-house pots as described in
reference to these several Figures 1 to 15, is that the "walls" or "shells,"
A, B, and D, are each free to expand and contract longitudinally and laterally
to a considerable extent independently of each other, and at different ratios
according as they are subjected to great or sudden changes of heat or cold
in their use.
This power of individual expansion of the "walls" A, B, and D,
together with their number and thinness, allows each of them to get sooner
and more regularly heated, which properties very much lessen the causes and
chances of fracture and breakage to each, particularly to the inner "shells "
or "walls"marked A, as even should the outer ones B and D be subjected
to a sudden and violent or irregular heat which would crack or fracture them,

page_text: B
or the whole vessel as heretofore constructed, the flaw can at first only go in
as far as the first parting E or C, leaving the inner "shell" A quite whole as
the heat gets distributed to a great extent before reaching it.
Figure 16 is a half vertical elevation and section of the lower part or close
end portion of a D shaped retort, similar to that shown and described in
reference to Figures 1 and 2, as in the act of being constructed out of fire-
clay, or any of the other plastic clays or materials, or mixtures of them with
other matters usually employed for the manufacture of such vessels, in accord-
ance with one modification of my improvements. Figure 17 is a horizontal
section of the same arrangement taken on the line 1-1 in Figure 16, to which
t corresponds. This arrangement is more particularly for the construction of
parallel retorts and other similar vessels of various transverse section, such as
shown in Figures 1, 5, 6, and 7, having two or more thicknesses of "walls"
A, B, with one or more corresponding partings C, constructed in accordance
with the main feature of my Invention, and which is an adaptation of one of
the present modes of constructing such vessels, to the practical working out of
the main feature of my Invention to the said modifications or applications.
In proceeding according to this modification delineated in Figures 16 and
17, the retort is "built" or " moulded" in a vertical position on end, out of
the soft clay around a parallel "core piece" of the same transverse section as
the interior of the retort or other vessel to be constructed by hand, with the
assistance of "mould boards" or " templets" for the true "thicknessing" and
shaping of the "walls" and their outer surfaces.
When the retort, as shown in Figure 2, is to have a close end with two
thicknesses and a "parting" between them, the lowest or outer layer B¹ is first
laid down as shown in Figures 16 and 17, by preference of half the usual thick-
ness, and laterally as large all round as the outside of the retort, or so as to fill
the inside of the "mould board" indicated by dotted lines at d, which shapes
the outer surface of the retort. Upon the top of the layer B', one or more
thicknesses of paper, felt, cloth, or other thin material destructible by moderate
heat is placed as indicated at C³, and over this is formed or laid the second
layer A', about the same thickness as the first B', but considerably smaller
laterally, and so as just to suit the inside of the "mould board" indicated at
d', which forms the outer surface c, of the inner vertical wall "A" of-the
retort.
The "core piece F, in this case of a D shape, which forms the interior
surface is now placed vertically in the centre of the inner layer or end A', and
then the inner vertical "wall" A, is formed round it to about the same
thickness as A', to which is united so as to form and complete the solid

page_text: inner shell A, A', of the vessel, as high as the "core piece" F. When the
outer surface c, of the layer A, is properly shaped and made to the proper
thickness by the "mould board" indicated at d', then one or more thicknesses
of paper, felt, or other substance to form the "parting "is rolled round it as
indicated at C, so as to join with C', and form a complete unbroken thin layer
or "parting" all round and across the bottom and up the sides of the retort
as far as it has been formed to the height of the "core piece" F. The outer
layer or thickness B, of clay or other plastic mixture, is then shaped or formed
by hand and the "mould board" indicated at d, all round the "parting "C, and
so combined with the lower layer B', of the close end, as to form the solid
outer "shell" or case B, B', of the retort, to within a few inches of the top of
the "parting" C, as indicated at c¹.
The walls of the retort being now formed to the height of the "core piece" F,
in its first position, it is raised inside in the usual manner nearly the whole height
of itself, or to near the top of the first or lower portions of the "walls" A, B, of
the retort which have just been described as formed, for the purpose of forming
or "raising" the "walls" A, B, to a second step or height. The inner layer
A is then formed or "carried up" by hand the "mould board" d¹, as
before described, to nearly the height of the "core piece" F, in its raised
position, as shown in this stage of the construction in Figure 16.
"
One or more thicknesses of paper or other substance C, before described as
used for forming the "parting," is now rolled round the outer surface c, of this
last formed part or height of the layer A, so as to join and form one unbroken
thin division or "parting" with the few inches at c¹ of the first length or
height of "parting" substance C left above the outer layer or "wall" B for
the purpose. The outer wall B is then "carried up or formed. to within a
few inches of the top of the last formed part or length of the inner layer A,
and the "parting" C, round it, as before described in reference to forming the
first or lower portion of the "wall" B, when the "core piece" is again raised
as before, and the operation of moulding or forming the two "walls" A, B,
and "parting" C of the retort in lengths or stages is repeated or proceeded
with until it has attained the required height.
When the open end or "mouth" of the retort is required to be for a
certain length of one great thickness, as shown from 6 to 6' in Figures 2, 3,
and 8, the forming of the parting C is stopped at the required height as at b,
and the two "walls" A and B are joined and formed into an open thick end
or "mouth piece" of the required shape in any of the usual manners now
employed.
When the retort or other vessel is required to have the double "walls"

page_text: A, B, and the "parting" C, only throughout a portion of its body or trunk, as
shown from a to 6 in Figure 3, the solid close end A2, and the sides as far up the
body as desired to be solid, are constructed in the usual manner, and then the
forming of my improved double "walls" A, B, and parting C, is begun and
proceeded with to the required height, in any of the manners herein described
under my improvements for forming the vertical or parallel portions of such
vessels, and particularly in reference to Figures 16, 17, and those yet to follow
under Figures 18, 19, 20, and 21.
Figure 18 is a half vertical elevation and section of another arrangement
for constructing parallel vessels and retorts according to my improvements;
and Figure 19 is a horizontal section of the same taken on the line 2-2 in
Figure 18, to which it corresponds.
In this arrangement it is a cylindrical retort, which is shown as in the act
of being constructed similar to that shown in Figures 5 and 8; and the
general procedure of forming the close end when there is one, whether double,
as shown at A, B, with a parting C, in Figure 16, or solid, as shown at
A2, Figure 8, is the same as described in reference to these Figures, as well
as the general operation of forming the vertical "walls"A and B around the
" core piece "F, which is much similar.
The new feature in this modification, shewn in Figures 18 and 19, being
that of forming the "parting " C, by a thin annular ring G, shewn detached
in vertical and horizontal section in Figures 20 and 21 respectively. This
ring G is placed vertically, and concentric to the "core piece "F, at the base
of the retort where the vertical "walls" A and B are begun to be formed,
and the former layer A is either formed round the "core piece " F to its
proper thickness by hand and the "mould board" d'; and the ring G then
brought up over it, or this inner layer A, may be formed in the annular space
between the "core piece" F and the ring G, as they are both raised from
time to time for that purpose in the same manner as the "core piece" F is
at present raised in the construction of such vessels. The outer wall B is
formed or "built up" round the outside of the ring G by hand, and shaped by
the "mould board" d to the proper height as the "core piece" F and ring G
are raised for that purpose from time to time. The raising or withdrawing of
the ring G, as the "walls" A and B are formed, leaves the narrow annular
space or "parting" C between them, as shown in Figures 18 and 19; this
hollow "parting "C may either extend out to the extreme open end of the
retort, as shown at 6', in Figures 4, 9, 10, 12, and 15, or be stopped short of
that as at b, and the two "walls" A and B joined so as to form a solid open
"mouth," as before described in reference to b, b', in Figures 2, 3, 8, 11,

page_text: and 14.
This narrow annular hollow "parting" C may, in some cases, be
filled up with any fine dust which would not solidify or adhere to the adjacent
surfaces of the "walls" A and B in the kiln-drying.
The two "walls" or "shells "A and B of the tubular retort, shown in
Figure 9, and the parallel portions as from a to b, in Figures 2, 3, and 8, of
whatever transverse section, as those shown in Figures 1, 5, 6, and 7, might
each be made separately in the ordinary clay-pipe making machine, and when
cut off to the required length inserted into each other, the outside of the
inner one A being slightly less than the inside of the outer one B so as to
prevent the adhesion of their adjacent surfaces and admit of the required
"parting" C, and the consequent power of the individual expansion of the
"walls" A and B, and the advantages resulting therefrom.
When strong ends or "mouth-pieces "are required, they can then be formed
on and united to the two "walls" A and B, as indicated in dotted linės at
a, b, in Figure 9, and before described in reference to b, b, in Figures 2, 3,
and 8.
Double or triple "walled" vessels of a conical or other irregular shape, as
shown in Figures 10 to 15 inclusive, may be constructed according to my
improvements, by first making each layer or thickness of "shell" A, B, and D,
as individual vessels, according to any of the several methods now in use for.
the particular class of vessels to be made, and inserting them into each other
either with a hollow narrow annular space between them, or introducing a
thin substance, such as before described in the former modifications, to form
the partings C and E between the greater portion of their adjacent sur-
faces; and when desired the two "walls" A and B may be united so as to
form a solid rim or "mouth," as before described and shown as at b, b', in
reference to Figures 2, 3, 8, 11, and 14.
.
Instead of using paper, felt, or cloth in the web or sheet to form the
"partings" C, they may be formed by brushing over the surface of the first
formed layer or thickness of clay, as A in the several modifications before
described, one or more coats of any pulpy mixture of vegetable or animal
matter capable of being reduced or destroyed in the baking or kiln-drying of
the vessels, such as those employed for making the coarser kinds of paper and
felt, or in some cases the substances used for forming the "partings" of the
"mould and cores" in ironfounding, and which would leave a partial hollow
space or perfect "parting" between the adjacent surfaces, over which the
forming of the next layer or thickness B is proceeded with as described in
reference to Figures 16 and 17.

page_text: This mode of forming the "partings" C is more particularly applicable to
the construction of curved and irregular shaped vessels, such as those shown in
Figures 11 and 12.
It is preferred in some cases to pierce the outer "walls" or "shells" B and
D of the vessels while in their soft or plastic state with small lateral holes e,
shown in most of the Figures, so as to admit of the escape of the gases which
would be engendered by the destruction of the substance forming the
"partings" C in the kiln while being baked.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I may observe that 1 do not confine or restrict myself to the precise
arrangements or general forms of the vessels which I have had occasion to
describe and delineate, as many deviations may be made therefrom and yet
retain the main or essential feature of my Invention; neither do I claim the
general forms or the modes of "building" or constructing these or such vessels
which I have bad occasion to describe and refer to individually or as a process,
except in so far as they are connected with, have reference to, and affect the
main or essential feature of my Invention; but what I consider to be novel
and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent is, the forming or constructing the
whole or the greater part of the sides and ends, "walls" or "bodies" of
retorts, crucibles, glass-house pots, and other similar hollow vessels subject
to great heat or sudden changes, or action of heat and cold, in their use, of
two or more layers or thicknesses, of whatever material they may be made,
with or having narrow spaces, divisions, or distinct "partings" left or formed
between their adjacent surfaces, substantially as herein-before described, or
any mere modification thereof.
In witness whereof, I, the said James Gillespie, have hereunto set my
hand and seal, this the Fourteenth day of June, in the year of our
Lord One thousand eight hundred and sixty-five.
JAMES GILLESPIE. (L.S.)