IMPROVEMENTS IN PRE- VENTING THE ESCAPE OF HEAT FROM STEAM BOILERS AND OTHER HEATED SURFACES
Year: 1863

page_text: LETTERS PATENT to Edwin Hargraves, of the City of Manchester, in
the County of Lancaster, for the Invention of "IMPROVEMENTS IN PRE-
VENTING THE ESCAPE OF HEAT FROM STEAM BOILERS AND OTHER HEATED
SURFACES."
Sealed the 10th May 1864, and dated the 14th November 1863.
PROVISIONAL SPECIFICATION left by the said Edwin Hargraves at
the Office of the Commissioners of Patents, with his Petition, on the
14th November 1863.
I, EDWIN HARGRAVES, of the City of Manchester, in the County of
Lancaster, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN PREVENTING THE ESCAPE OF HEAT FROM STEAM BOILERS AND OTHER
HEATED SURFACES," to be as follows:-
I coat the exposed portions of steam boilers, steam. pipes, or other heated
surfaces with plaster of Paris, mixed with a little water, the coat of plaster
when set into a hard mass is found to be effective in preventing the escape of
heat; or I mix with the plaster of Paris fibrous or other substances, such as
bair or similar materials, so as to make the mass adhere more solidly to the
surface.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Edwin Hargraves in the Great Seal Patent Office on the
14th May 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, EDWIN
HARGRAVES,. of the City of Manchester, in the County of Lancaster, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of November, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-seventh year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Edwin Hargraves, Her special license that I, the said Edwin Hargraves,
my executors, administrators, and assigns, or such others as I, the said Edwin
Hargraves, 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 PRE-
VENTING THE ESCAPE OF HEAT FROM STEAM BOILERS AND OTHER HEATED SURFACES,"
upon the condition (amongst others) that I, the said Edwin Hargraves,
my executors or administrators, by an instrument in writing under my, or
their, or one of their hands and seals, should particularly describe and ascer-
tain 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 Edwin Hargraves, 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 (that is to say) :-
I coat the exposed portions of steam boilers, steam pipes, or other heated
surfaces with plaster of Paris, mixed with a little water; the coat of plaster
when set into a hard mass is found to be effective in preventing the escape of
heat; or I mix with the plaster of Paris fibrous or other substances, such as
hair or similar materials, so as to make the mass adhere more solidly to the
surface.
The method I prefer to adopt is to mix wood sawdust with the plaster of
Paris in the proportion of about three measures of wood sawdust to one

page_text: measure of dry plaster of Paris, the whole to be mixed with a little water and
applied to the surface of the boiler or other heated substance.
I do not confine myself to the exact proportions herein named, as they may
be varied without departing from the principle of the discovery; but I claim
the mixture of plaster of Paris with wood sawdust or other fibrous materials,
for the purposes herein mentioned.
In witness whereof, I, the said Edwin Hargraves, have hereunto set
my hand and seal, this Thirteenth day of May, in the year of our
Lord One thousand eight hundred and sixty-four.
Signed, sealed, and delivered by the
within-named Edwin Hargraves,
in the presence of
E. J. HUGHES,
Patent Agent,
Manchester.
EDWIN HARGRAVES. (L.S.)