IMPROVEMENTS IN THE ADAPTATION AND APPLICATION OF SLATE FOR PAVEMENTS, STEPS, LANDINGS, STREET CROSSINGS, AND OTHER SIMILAR USES
Year: 1875

page_text: LETTERS PATENT to Richard Gervase Elwes, of 7, Westminster
Chambers, in the City of Westminster, Civil Engineer, for the
Invention of "IMPROVEMENTS IN THE ADAPTATION AND APPLICATION OF
SLATE FOR PAVEMENTS, STEPS, LANDINGS, STREET CROSSINGS, AND OTHER
SIMILAR USES.”
Sealed the 15th June 1875, and dated the 16th April 1875.
PROVISIONAL SPECIFICATION left by the said Richard Gervase Elwes
at the Office of the Commissioners of Patents, with his Petition,
on the 16th April 1875.
I, RICHARD GERVASE ELWES, of 7, Westminster Chambers, in the
City of Westminster, Civil Engineer, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN THE ADAPTATION AND APPLICATION
OF SLATE FOR PAVEMENTS, STEPS, LANDINGS, STREET CROSSINGS, AND OTHER SIMILAR
USES," to be as follows:-
My Invention has for its object the adaptation of blocks or slabs of
slate for use in paving, and for similar purposes, by forming grooves
in the surface thereof in the manner hercin-after described, whereby the

page_text: slipperiness of ordinary slate slabs is obviated, and a firm foothold
obtained; also dampness prevented, and the appearance of the pavement
or other surface improved.
Slabs of slate as ordinarily manufactured when used for paving
purposes are slippery by reason of the smoothness of their surface, and
being non-absorbent in quality retain water on the surface.
Now my Invention is intended to remedy these defects by grooving
the surface of the slabs in such a manner as to supply a firm foothold
thereon, and to allow water to pass off as required.
The size or section of the groove may be varied, but it is preferred
to be trough shaped, and from one quarter to three-eighths of an inch
in depth, and from threc-eighths to five-eighths of an inch in width
at the top with a level bottom, and with the sides inclined to an angle
of about forty-five degrees. This section of groove is preferred because
the edges of such grooves are less liable to chip than those of other
sections. The grooves may either be parallel or crossing cach other
at right angles, or diagonally, so as to divide the surface into squares,
diamonds, or other patterns, and they may be set at any convenient
distance apart. When parallel grooves are used it is preferred to place
them at about half an inch apart, and grooves crossing each other at
right angles or diagonally are by preference set at about two or three
inches apart. Parallel grooves set close together for steps or landings
arc by preference intended to be arranged so as to run diagonally across
the steps or landing at an angle of about forty-five degrees to the
long side of the step or landing, as this is found to give the best
foothold.
In order to cut or form the grooves an ordinary grooving tool ground
to the required shape, and fixed in an ordinary planing or shaping
machine, may be employed, but the grooves may be cut or formed by

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Richard Gervase Elwes in the Great Seal Patent
Office on the 13th October 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
GERVASE ELWES, of 7, Westminster Chambers, in the City of West-
minster, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Sixteenth day of April, in the year of
our Lord One thousand cight hundred and seventy-five, in the thirty-
eighth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Richard Gervase Elwes, Her special licence
that I, the said Richard Gervase Elwes, my executors, administrators,
and assigns, or such others as I, the said Richard Gervase Elwes, 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
Ircland, the Channel Islands, and Isle of Man, an Invention for "Iм-
PROVEMENTS IN THE ADAPTATION AND APPLICATION OF SLATE FOR PAVEMENTS,
STEPS, LANDINGS, STREET CROSSINGS, AND OTHER SIMILAR USES," upon the con-
dition (amongst others) that I, the said Richard Gervase Elwes, 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
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 Richard Gervase Elwes, 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) :-
My Invention of "Improvements in the Adaptation and Application
of Slate for Pavements, Steps, Landings, Street Crossings, and other
similar Uses," has for its object the adaptation of blocks or slabs of slate
for use in paving and for similar purposes, by forming grooves in the
surface thercof in the manner herein-after described, whereby the

page_text: slipperiness of ordinary slate slabs is obviated, and a firm foothold
obtained; also dampness prevented, and the appearance of the pavement
or other surface improved.
Slabs of slate as ordinarily manufactured when used for paving
purposes are slippery, by reason of the smoothness of their surface, and
being non-absorbent in quality retain water on the surface.
Now my Invention is intended to remedy these defects by grooving
the surface of the slabs in such a manner as to supply a firm foothold
thereon, and to allow water to pass off as required.
The size or section of the groove may be varied, but it is preferred
to be trough shaped, and from one quarter to three-cighths of an inch
in depth, and from three-eighths to five-eighths of an inch in width
at the top with a level bottom, and with the sides inclined to an angle
of about forty-five degrees.. This section of groove is preferred because
the edges of such grooves are less liable to chip than those of other
sections. The grooves may however be made of various sections,
V shaped, trough shaped, segmental, or otherwise, and deep or shallow,
as may be desired. They may also be arranged in a variety of different
ways. Thus for steps it is preferred to use a number of grooves
running diagonally across the tread, and placed close together, all
the grooves parallel to each other. For an inclined surface, as the
foot pavement of a street, or the floor of a stable, grooves are intended
to be used of about three inches apart, crossing each other at an acuto
angle so as to divide the surface into diamond or lozenge-shaped
eminences. For a flat surface grooves crossing each other at right
angles form the simplest pattern, but for ornamental purposes a great
variety of patterns may be introduced. Thus the centre of a courtyard
may consist of a boss ornamented with a series of intersecting circles
resembling the engine turning on a watch. This may be enclosed in a
square of plain slab surrounded by a border of the lozenge pattern,
alternating with strips of a plain slab, and so on.
In order to cut or form the grooves one or more ordinary grooving
tools ground to the required shape, and fixed in an ordinary planing
or shaping machine, may be employed; but the grooves may be cut or
formed by other suitable means.
Slabs of slate when grooved on their surface in the manner described

page_text: may be formed into pavements or floorings, affording good foothold, and
free from inconvenient moisture, and ornamental in appearance.
Having thus described the nature of the said Invention, and in what
manner the same is to be performed, I hereby declare that what I claim
as of my Invention is, the adaptation and application to paving purposes
and other uses of blocks or slabs of slate by grooving the surface of the
same in the manner herein-before described.
In witness whereof, I, the said Richard Gervasc Elwes, have here-
unto set my hand and seal, the Eighth day of October, in
the year of our Lord One thousand eight hundred and seventy-
five.
Witness,
RICHARD GERVASE ELWES. (L.s.)
CLARMONT ALFRED SKRINE,
49, Charlwood St.,
London,
Occupation, Gentleman.