IMPROVEMENTS IN THE MANUFACTURE OF FUEL
Year: 1840

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
STIRLING, of Limehouse, in the County of Middlesex, Patentee of the Rapid
Filterer, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Letters Patent under the Great Seal of Great Britain, bearing date at West-
minster, the Twentieth day of March, in the third year of Her reign, did,
for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Stirling, Her especial licence, full power, sole privilege and authority,
that I, the said Thomas Stirling, my exors, adñors, and assigns, or such others
as I, the said Thomas Stirling, my exors, admors, 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 FUEL;" in which said
Letters Patent is contained a proviso that I, the said Thomas Stirling, 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 thereunto had, will more fully and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Thomas Stirling, do hereby declare the nature of my said Invention, and the

page_text: manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof (that is to say) :-
Various attempts have been made of late years to manufacture fuel from
small coal with tar and pitch or other such bituminous matters combined with
clay or such like earth, and to mould the same into blocks, and by pressure to
get such blocks into as hard a consistency as possible. Now the object of my
Invention is to submit manufactured fuel from such materials to the process of
artificial heat whilst in the moulds, whereby I am enabled to produce most
beneficial effects by rendering blocks of such fuel more enduring even under
combustion than when made according to processes which have heretofore
been resorted to. And although my Invention does not relate to any particular
combination of quantities of the materials of which the fuel to be manufactured
according to my Invention are to be composed, yet in explaining the best means
of carrying out my Invention, I will describe a composition of fuel such as I
usually make, and which I believe will be found the best relative proportions
of the materials; at the same time I wish it to be understood that I do not
confine myself to the quantities herein mentioned, as my Invention above
stated does not consist of the compound but in the mode of treating such
compounds by a process of heat in moulds. The relative combination of
parts I prefer to use is as follows:-One hundred pounds of vegetable tar,
three hundred pounds mineral or coal tar, two thousand two hundred and forty
pounds of small coal, which should pass through a sieve of six holes or meshes
to each square inch. Clay dissolved in water to the consistence of tar, of
which solution one hundred and five pounds; other ingredients may be mixed
therewith, as heretofore, but I do not consider it desirable or beneficial so to
do. I prefer to mix these matters in the following manner :-I heat the tar
in an iron vessel, and stir in the solution of clay, and boil up the compound,
then run off such boiling mixture into another pan or vessel placed over a
furnace to keep the compound as fluid as possible; and as it flows in I gradually
pour in and mix the small coal as intimately as possible, keeping the whole
well stirred; and when thoroughly mixed, I put the fuel, thus far made, into
moulds of the size desired. I prefer using rectangular cast-iron moulds
similar to brick moulds, but I have several moulds combined together, so as
to be capable of moulding several blocks at the same time. I place the com-
pound or fuel into these moulds as soon as mixed as above described, and then
place the moulds so filled into an oven or kiln kept heated to two hundred
and fifty degrees to three hundred degrees of Fahrenheit, and let them remain
therein for an hour or an hour and a half. I then withdraw them, and
permit the blocks of fuel to cool in the moulds, and when cold are removed

page_text: from the moulds. The fuel will be immediately fit for use. I would remark
that, although I have been thus particular in stating the exact particulars of
the process as pursued by me in carrying out my Invention, at the same time
I do not confine myself thereto.
Having thus described the nature of my improvements, I would have it
understood that what I claim as the Invention secured by the above-recited
Letters Patent is the mode of manufacturing fuel from small coal, tar, and
clay, by submitting the same in moulds to a considerable degree of artificial
heat when in moulds, as above described.
In witness whereof, I, the said Thomas Stirling, have hereunto set my
hand and seal, this Eighteenth day of September, One thousand eight
hundred and forter