A NEW OR IMPROVED COMPOSITION FOR MAKING OR FORMING ROADS, PATHS, AND OTHER LIKE SURFACES
Year: 1871

page_text: LETTERS PATENT to Robert Dutton Grindley, of Highgate, in the
County of Middlesex, Manufacturing Chemist, for the Invention of
"A NEW OR IMPROVED COMPOSITION FOR MAKING OR FORMING ROADS,
PATHS, AND OTHER LIKE SURFACES."
Sealed the 5th January 1872, and dated the 3rd November 1871.
PROVISIONAL SPECIFICATION left by the said Robert Dutton Grindley
at the Office of the Commissioners of Patents, with his Petition,
on the 3rd November 1871.
I, ROBERT DUTTON GRINDLEY, of Highgate, in the County of Middle-
sex, Manufacturing Chemist, do hereby declare the nature of the said
Invention for "A NEW OR IMPROVED COMPOSITION FOR MAKING OR FORMING
ROADS, PATHS, AND OTHER LIKE SURFACES," to be as follows:-
My composition consists of ground granite and pitch, bitumen, or other
analogous binding material, tar for example. The granite and the pitch
or other analogous material may be ground together, or they may be
ground separately and be afterwards mixed together and thoroughly

page_text: incorporated. The proportion of pitch or other analogous material
employed should be about 20 per cent., or sufficient to bind the particles
of granite together when the mixture is submitted to the action of heat
and then allowed to cool.
In making or forming roads, paths, or other like surfaces with my
composition I prefer to proceed as follows:-I first lay down a foundation
of gravel and cement, or other substances such as are ordinarily laid
down as the foundation for bituminous or rock asphalte roads, and upon
this foundation I place a layer, say, 3 inches thick, more or less, of a
mixture of heated ground granite and pitch. I then submit this mixture
to the action of rammers or pressers, the result being that when the mass
cools the granite and pitch become one solid body adapted for carriage or
ordinary traffic.
I do not, however, confine myself to any particular mode of carrying
out this Invention, or to the employment of the pitch in a powdered
form, as it may be used in a liquid state, nor do I limit myself to the
laying down of the composition in the manner above explained, as it may
be moulded and laid down in the form of blocks or slabs; for my
Invention essentially consists of a composition formed of ground granite
the particles of which are bound together by means of pitch or other
analogous material.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Dutton Grindley in the Great Seal Patent
Office on the 3rd May 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
DUTTON GRINDLEY, of Highgate, in the County of Middlesex, Manu-
facturing Chemist, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of November, in the
year of our Lord One thousand eight hundred and seventy-one, in
the thirty-fifth year of Her reign, did, for Herself, Her heirs and
successors, give and grant unto me, the said Robert Dutton Grindley,
Her special licence that I, the said Robert Dutton Grindley, my
executors, administrators, and assigns, or such others as I, the said

page_text: in the manner above explained, as it may be moulded and laid down in
the form of blocks or slabs; for my Invention essentially consists of a
composition formed of ground granite the particles of which are bound
together by means of pitch or other analogous material.
In witness whereof, I, the said Robert Dutton Grindley, have here-
unto set my hand and scal, this First day of May One thousand
eight hundred and seventy-two.
R. D. GRINDLEY. (L.S.)