IMPROVEMENTS IN STOVES AND STOVE GRATES
Year: 1864

page_text: LETTERS PATENT to John Jobson, of Derby, in the County of Derby,
Ironfounder, for the Invention of "IMPROVEMENTS IN STOVES AND STOVE
GRATES."
Sealed the 9th December 1864, and dated the 20th June 1864.
PROVISIONAL SPECIFICATION left by the said John Jobson at the
Office of the Commissioners of Patents, with his Petition, on the
20th June 1864.
I, JOHN JOBSON, of Derby, in the County of Derby, Ironfounder, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN STOVES AND
STOVE GRATES," to be as follows, that is to say:
My Invention consists of improvements upon the description of stoves and
grates generally known as Sylvester's or the Gill apparatus, in which the heat
is evolved from a series of fins or plates; these fins or plates have usually
been constructed of such form that their greatest evolving surface is found at
the point farthest from that at which the heat is generated. I propose to
make the fins or plates of such form that their greatest evolving surface shall
be immediately contiguous to the fire. The form of the firegrate I prefer to
make conical, the apex of the cone being below, and underneath the cone
I form a cylindrical or other shaped passage for air, and also for ashes by
fitting such passage with a similarly shaped pan or receptacle for dust and
ashes, and which pan can be readily withdrawn from the front. The plate or
fin I make in some instances to surround entirely the air passage. To avoid

page_text: the accidental splitting of the plates by expansion and contraction I cast them
slightly grooved under the bed of the fire-grate and under the air passage, so
that the metal being thinner at those parts will give way there.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Jobson in the Great Seal Patent Office on the 19th
December 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
JOBSON, of Derby, in the County of Derby, Ironfounder, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twentieth day of June, in the year of our Lord
One thousand eight hundred and sixty-four, in the twenty-eighth year of
Her reign, did, for Ierself, Her heirs and successors, give and grant unto
me, the said John Jobson, Her special licence that I, the said John
Jobson, my executors, administrators, and assigns, or such others as I, the
said John Jobson, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
STOVES AND STOVE GRATES," upon the condition (amongst others) that I, the
said John Jobson, by an instrument in writing under my hand and seal,
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 John Jobson, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Drawings hereunto annexed, and to the
letters and figures marked thereon (that is to say) :-
:-
My Invention consists of improvements upon the description of stoves and
grates generally known as Sylvester's or the Gill apparatus, in which the heat
is evolved from a series of fins or plates; these fins or plates have usually
been constructed of such form that their greatest evolving surface is found at
the point farthest from that at which the heat is generated. I propose to
make the fins or plates of such form that their greatest evolving surface shall

page_text: be immediately contiguous to the fire. The form of the fire chamber or grate
I prefer to make conical, the apex of the cone being below and underneath
the cone.
I form a cylindrical or other shaped passage for air, and also for
ashes, by fitting such passage with a similarly shaped pan or receptacle for
dust and ashes, and which pan can be readily withdrawn from the front. The
plate or fin I make in some instances to surround entirely the air passage, so
as to form a close ash-pit under the fire, closed also in front with a door or
other piece and fitted with a valve or ventilator to regulate the supply of air
to the fire, so that the combustion of the fuel and the heat of the stove can
be fully regulated. It is obvious that this arrangement also ensures an
economical use being made of the heat evolved from the bottom of the fire,
which has heretofore been mostly lost, and it also causes the stove itself to be
safer as regards setting fire to buildings as the fins or gills surrounding the
closed ash-pit are of a size sufficient to cause their edges that rest upon the
floor to be warm only when the stove is in full work.
I will now proceed to give a more explicit description of my Invention by
the aid of the annexed Drawings, which represent in several views of each
various forms of stoves constructed according to my improvements.
Figure 1 is a front elevation of one of the ordinary forms of these gill
stoves; Figure 2, a side elevation of the same; Figure 3, a longitudinal
vertical section, taken through the centre of the stove from front to back;
Figure 4, a transverse vertical section taken between the plates, and shewing
the shape of the plate in elevation; Figure 5, a plan on the line (A, A,
(Figure (4); and Figure 6 a like plan on the line B, B.
Referring to these Figures (a) shews the fire chamber; (b), the fire-bars;
(c), the close ash-pit and air passage, consisting in this instance of a cylindrical
aperture (though any other form than circular may be employed if preferred)
through each plate to admit the insertion of a similarly shaped pan or drawer
to receive the dust and ashes; (d) is a groove formed on either side the top of
the fire chamber to receive a flange upon the under side of the loose cover, and
thus keeping such loose cover always in place; and this groove being filled
with cement or other suitable substance, the joint is thereby rendered smoke-
tight, the cover is omitted in Figure 4 merely for the convenience of the
drawing; (e) shews the fins or plates. From this description of the parts of
this stove it will be seen that the very form of the fire chamber (a), being that
of an inverted cone, necessitates the greatest superficial area of the heat
evolving plates (e) being at the point where such heat is generated, or as
nearly as possible at the level of the under side of the fire-bars, the smallest
superficial area of the plates being at the point farthest from the fire, or at

page_text: the top of the stove, and it is in the development of this principle that the
spirit of my
Invention lies. The remaining Drawings illustrate a few more
forms of the stove, all sharing the same principle of construction as regards
the plates, but that seen in Figures 7 to 11, inclusive, being constructed with
an open air passage and ash-pit instead of a closed one, Figures 12 and 13
shewing a form of stove with the plate carried round the top, but still having
its greatest heat evolving area contiguous to the fire, and Figures 14 and 15
merely serving to indicate the application of the principle to register stove
grates.
Having thus described the nature of my said Invention, and the manner
in which the same is to be performed, I do not limit myself to these precise
details, nor to any particular form of the plates for these stoves, or of the stoves
themselves; but that which I claim is,―
Firstly, the improvements in the construction of the description of stove
termed the Sylvester or Gill stove, and in stove grates made upon this principle
by making the plates or fins for such stoves and grates of such form that the
greatest extent of heat evolving surface is obtained at the point nearest to
the fire.
Secondly, I claim the forming of the ash-pit and air passage in the body
of the plate, so as to be surrounded by the gill or fin, as herein described.
And, thirdly, I claim the forming of a groove on the top of the gill plates,
which groove is to receive the flange of the loose top and also to hold cement
or other suitable substance to make the joint smoke-tight, as herein more
fully set forth and specified.
In witness whereof, I, the said John Jobson, have hereunto set my hands
and seal, this Fifteenth day of December, in the year of our Lord
One thousand eight hundred and sixty-four.