IN- PROVEMENTS IN THE CONSTRUCTION OF ROADS OR OTHER SURFACES FOR TRAFFIC, AND IN THE Apparatus to be USED IN CONSTRUCTING THE SAME.” PROVISIONAL SPECIFICATION
Year: 1871

page_text: LETTERS PATENT to David Crawford Proudfoot, of Edinburgh, in the
County of Mid Lothian, North Britain, for the Invention of "IN-
PROVEMENTS IN THE CONSTRUCTION OF ROADS OR OTHER SURFACES FOR TRAFFIC,
AND IN THE Apparatus to be USED IN CONSTRUCTING THE SAME.”
PROVISIONAL SPECIFICATION left by the said David Crawford
Proudfoot at the Office of the Commissioners of Patents, with his
Petition, on the 3rd April 1871.
I, DAVID CRAWFORD PROUDFOOT, of Edinburgh, in the County of
Mid Lothian, North Britain, do hereby declare the nature of the said
Invention of "IMPROVEMENTS IN THE CONSTRUCTION OF ROADS OR OTHER
SURFACES FOR TRAFFIC, AND IN THE APPARATUS TO BE USED IN CONSTRUCTING THE
SAME," to be as follows, that is to say :-
This Invention has for its object the construction of roads, streets,
footpaths, courtyards, or other similar surfaces so that they are
not only more durable than when constructed according to methods
hitherto adopted, but they are by the present Invention constructed at
a diminished first cost and in less time.

page_text: "
In constructing the said surfaces the ground is excavated or prepared
to the required depth and curvature, and then consolidated by rolling
with a heavy roller until it is rendered uniform throughout, after which
and only in cases where it becomes necessary by reason of the ground
being naturally soft, or having been embanked, a thin coating composed
of cement and water, or of cement, sharp sand, or fine gravel and
water, or of hydraulic or non-hydraulic lime and water, or of such
lime, sharp sand, or fine gravel and water, and in any case where
deemed necessary iron dust, the proportions of the materials being
such as will produce a composition resembling common mortar in
moisture and solidity, is laid on so as to form a skin over the prepared
surface of the ground, in order to prevent under damp from ascending
to the road or other surface for traffic, also to retain the 'grout,"
hereinafter referred to, from descending into the subsoil. Over the
bottom so prepared broken stones, which may be of granite, porphyry,
whinstone, freestone, gravel, slag, or other similarly suitable materials
are laid loosely, and to an uniform depth, which may be for ordinary
purposes about four inches, but when the traffic is very heavy two or
more such layers may be employed. The whole of the loose materials
so laid down is then thoroughly moistened with water and immediately
thereafter is "grouted" with a fluid mixture or "grout" composed
either of cement and water, or of cement, sharp sand, or fine gravel
and water, or of hydraulic or non-hydraulic lime and water, or of such
lime, sharp sand, or fine gravel and water and iron dust, also sawdust
of wood may be mixed with the other materials, the proportions of
the materials being such as will produce the hardness of surface required
for the traffic on the road.
66
"
The means or apparatus employed for mixing or commingling of the
materials of which the fluid mixture or grout" is composed and
also for distributing the mixture or grout" consists of a tank or
vessel, preferably of cylindrical form. The tank is provided with
gcaring for agitating and commingling the materials when placed in
it, and by means thereof the fluid mixture or grout is prepared for
use. The tank may either be mounted upon wheels, so that the
apparatus can be drawn or moved by animal or other power over the
surface to be "grouted," and in order to its being so used the bottom
of the tank is provided with a series of apertures, which are opened or
closed by a sliding plate provided with a similar set of openings, through
which the "grout" is discharged or prevented from being discharged

page_text: when required. Or the tank may be stationary, in which case the
fluid mixture or "grout " may be discharged and distributed by means
of a pump and hose or other appliances. The distribution should be
completed as rapidly as is practicable. After the surface of the road
is "grouted "and before the mixture has had time to harden, the
surface is pressed down by a heavy roller passed and repassed over
it until it is consolidated and rendered uniform, care being taken that
the rolling shall then cease. In the construction of roads or other
surfaces for heavy traffic the ground is excavated or prepared to the
required depth and curvature, and then consolidated by rolling with
a heavy roller until it is rendered uniform throughout; causeway stones
or other materials of uniform depth arc then laid over the ground,
being set "hard to hard and grouted together with a fluid mixture of
grout" of the kind herein-before referred to. The surface so treated
is then rolled and consolidated, after which broken stones or other
materials are laid over this surface and are grouted,” and it is
finished in a manner similar to that herein-before specified.
$6
"
"
The roller to be used in all of the foregoing operations should be a
steam roller, preferably not less than of fifteen tons in weight, but where
the use of such a roller is impracticable a heavy roller drawn by animal
power may be used.
The essential features of this Invention consist in the construction of
roads and other similar surfaces by applying a fluid mixture or "grout"
composed, prepared, and distributed as above described over surfaces.
covered with broken stones, slag, or other similar material, and by con- .
solidating the said surfaces by means of heavy steam or other rollers.
The proportions of the materials preferred to be employed for forming
the "grout" herein-before mentioned are about one part of cement or
lime to one part of fine gravel or sand, the proportions of the iron
dust or sawdust being variable in accordance with the nature of the
surface desired.
5
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Crawford Proudfoot in the Great Seal
Patent Office on the 2nd October 1871.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
CRAWFORD PROUDFOOT, of Edinburgh, in the County of Mid Lothian,
North Britain, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Third day of April, in the year of
our Lord One thousand eight hundred and seventy-one, in the 35th
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said David Crawford Proudfoot, Her special
license that I, the said David Crawford Proudfoot, my executors, admi-
nistrators, and assigns, or such others as I, the said David Crawford
Proudfoot, my executors, administrators, or 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 "In-
PROVEMENTS IN THE CONSTRUCTION OF ROADS OR OTHER SURFACES FOR TRAFFIC,
AND IN THE APPARATUS TO BE USED IN CONSTRUCTING THE SAME," upon the
condition (amongst others) that I, the said David Crawford Proudfoot,
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 David Crawford Proudfoot, 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, reference being had to the accom-
panying Drawings and to the letters and figures marked thercon, that
is to say:
My said Invention has for its object the construction of roads, streets,
footpaths, courtyards, or other similar surfaces so that they are not
only more durable than when constructed according to methods hitherto
adopted, but they are by the present Invention constructed at a
diminished first cost and in less time.
And in order that my said Invention may be properly understood I
now proceed more particularly to set forth the mode or manner in or
under which the same is or may be used or carried into practice, and
for the sake of more complete elucidation I have hereunto apponded
an explanatory Sheet of Drawings, on which Figure 1 represents a
transverse section of a road as constructed in accordance with one
modification of my said Invention.

page_text: In constructing the road now referred to the ground is first excavated
to the required depth and curvature, as shewn at Figure 1, after which
the surface thereof is consolidated or hardened by rolling it with a heavy
roller until it is rendered uniform throughout. When this is accom-
plished, and in cases where it becomes necessary by reason of the ground
being naturally soft or having been embanked, but not otherwise, a
prepared bottom a is formed on the surface of the ground so rolled in
order to afford a sufficiently firm foundation for the materials of which
the surface of the roadway is constructed, and also to prevent under
damp from ascending to the road, or the liquid material or grout
employed in constructing the road from descending into the subsoil.
The bottom a consists of a thin coating, as shewn at Figure 1, and
which is composed of cement and water, or of cement, sharp sand,
or fine gravel and water, or of hydraulic or non-hydraulic lime and
water, or of such lime, sharp sand, or fine gravel and water, and in
cases where it is deemed necessary iron dust may be added, the pro-
portions of the said materials being such as will produce a composition
resembling common mortar in consistency. Over the bottom a so
prepared broken stones, which may be of granite, porphyry, whinstone,
freestone, gravel, slag, or other similarly suitable material are laid loosely
for a length of about forty lineal yards at one time and to an uniform
depth as shewn at b, Figure 1, and which depth or thickness may be
for ordinary purposes about four inches, but when the traffic is very
heavy a depth equal to two or more such layers of broken stones may
be employed. The whole of the loose material so laid down is then
moistened with water by means of a water cart provided with distributors
or with a hose and rose, or by other suitable means, care being taken
that the whole of the materials laid down are made thoroughly damp.
Immediately on the watering being completed the loose materials are
grouted with a fluid mixture or grout composed either of cement and
water, or of cement, sharp sand, or fine gravel and water, or of hydraulic
or non-hydraulic lime and water, or of such lime, sharp sand, or fine
gravel and water, iron dust or sawdust of wood may be mixed with the
other materials, the proportions of the said materials being such as will
produce the hardness and roughness of surface necessary for sustaining
the traffic on the road.
The grout is distributed over the surface of the loose material by
means of a grout mixing and distributing apparatus now about to be
described, and in such a manner that the entire surface of that portion

page_text: of the road being operated upon shall be covered, and all the spaces and
interstices between the broken pieces of stone on the said portion of the
road filled with the fluid mixture or grout as quickly as is practically
attainable.
On Figure 1 of the accompanying Drawings the parts between the
loose stones shown in black represent the spaces filled with grout. The
apparatus whereby the materials of which the fluid mixture or grout
is composed are mixed or commingled, and the grout distributed is
illustrated in end elevation at Figure 2 of the Drawings, in plan at
Figure 3, in part transverse section on the line x, x, Figure3, at Figure 4,
and in part vertical section on the line 3, y, Figure 4, at Figure 5,
whilst Figure 6 is a detailed view of certain parts of the apparatus, and
which are herein-after more particularly referred to.
This apparatus consists of a tank or vessel A, preferably of a cylin-
drical form, as shewn on the Drawings. The tank or vessel A is
supported by a framing B, which is mounted on wheels C and D
respectively in order that the apparatus may be drawn or moved by
horses over the surface to be grouted. The tank or vessel A is provided
with a number of agitators or stirrers E, which are fixed to the axis F
of the wheels C and D, as more particularly shown on the transverse
section of the tank at Figure 4 and on the vertical section at Figure 5.
The end of the shaft F approximate to the wheel C is provided with a
handle G, and when the materials of which the fluid mixture or grout
is composed have been introduced into the tank or vessel A through
the opening I on the upper part thereof, shewn at Figures 3 and 4, the
agitators or stirrers E are rotated by means of the said handle G until
the whole materials are thoroughly mixed or commingled. On the
shaft F between the inner side of the wheel C and the outer side of the
framing B a perforated disc H is fixed, as shown at Figures 2 and 3, and
when the apparatus is about to be moved over the surface to be grouted
a pin a is inserted through a hole in one of the spokes or arms of the
wheel C into one of the perforations 6 in the disc H, as more particularly
seen at Figure 2, thereby, when the apparatus is moved, causing the
shaft F to rotate with the wheels C and D, and consequently also
revolving the agitators E, by which means the grout is kept in a
perfectly mixed state until it is discharged on to the surface of the road-
way being constructed. At the bottom or lower part of the tank or
vessel A a series of holes or apertures c are formed, as more particularly

page_text: secn at Figures 4 and 5, and which are opened and closed by means of
a sliding plate J, more particularly shewn at Figure 6, provided with a
similar set of apertures d, through which apertures c and d the grout
is discharged or prevented from being discharged by the plate J, as
required. The plate J slides in a guide K extending along the whole
length of the tank A, and is caused to open or close the apertures c by
actuating the hand wheel e fixed on the upper extremity of the shaft f
at the rear of the apparatus. By actuating the hand wheel e a pinion g
on the lower end of the shaft f is rotated, and being geared into a
rack fixed to the under side of the plate J, as shewn, causes the
said plate to move either to the right hand or to the left, and so open or
close the apertures c. In order that the sliding plate J and mechanism
connected therewith when not in use may be turned up from proximity
to the ground in transmitting the apparatus from one place to another,
and thus prevent them from sustaining injury, a pitch chain L is
attached to the tank or vessel A, as shewn at Figures 2 and 3. The
chain L is passed over a pitch wheel or drum M, shewn at Figure 3, and
which is fixed on a transverse shaft k supported in standards / fixed to
a transverse beam &, as shewn at Figure 3. The shaft k is provided
with a handle n, by which it and the pitch wheel M are rotated, and the
tank or vessel consequently turned into any desired position. The
tank A is retained in the position to which it is adjusted by providing
the shaft with a perforated disc m, into one of the openings o formed
in which the upper extremity of a pall or catch pin p is entered, its
lower end being attached loosely to one of the shafts of the apparatus,
as shewn at Figures 2 and 3. In lieu of employing a tank mounted on
wheels, as herein-before described and shewn on the annexed Drawings,
in which to mix the grout and to distribute it, a stationary tank may be
employed, in which case the fluid mixture or grout may be discharged
and distributed by means of a pump and hose, or by other suitable
apparatus, in any case the distribution being completed in as rapid a
manner as is practicable.
After the surface has been grouted in either manner herein-before
described, it is pressed down and consolidated before the mixture has
had time to harden on the surface by passing and repassing a heavy
roller over it until it is rendered uniform, care being taken that the
rolling shall cease immediately thereafter.
It is to be here understood that though the method of construction
herein-before specified is shewn and described in reference to roadways,

page_text: it is equally adaptable to footpaths, courtyards, or other similar surfaces
for traffic.
Under another modification of my Invention the road or other surface
when intended to sustain unusually heavy traffic may be constructed as
shewn at Figure 7 of the Drawings. The ground in this instance is
excavated or prepared to the required depth and curvature, and then
consolidated by rolling it with a heavy roller, as herein-before set forth,
until it is rendered uniform throughout. Causeway stones of uniform
depth are laid over the ground so prepared, as shown at A, Figure 7, on
the accompanying Sheet of Drawings, being set "hard to hard" and
grouted together with the fluid mixture or grout herein-before referred
to.
After being thus treated the surface is rolled and consolidated,
after which a layer of broken stones or other material is spread over the
surface, as shewn at B, Figure 7, and the road is finished by grouting
and rolling it in the manner herein-before specified with reference to
the first system of construction.
In all the foregoing operations of rolling it is preferred to use a steam
roller of not less than fiftecu tons in weight, but where the use of such
a roller is impracticable a heavy roller drawn by horses, or otherwise,
may be employed.
The proportions of the material preferred to be employed for forming
the fluid mixture or grout hercin-before mentioned are about one part
of cement or lime to one part of fine gravel or sand, the proportions of
the iron dust or sawdust being variable according to the nature of the
surface desired.
Amongst other advantages accruing from the Invention arc, that the
roads, streets, courtyards, footpaths, and other surfaces for traffic con-
structed in accordance therewith are not only rendered more durable
than when constructed in accordance with existing methods, but they
are also constructed at a diminished first cost and in less time, and are
more easily kept clean and repaired than existing arrangements of
macadamized or causewayed streets or roads admit of; also, when it is
necessary to make openings in the road or street in order to lay or
repair gas or water pipes, the herein-before described construction of
road or strect enables the openings to be closed more easily and
effectually than pertains to the ordinary construction of roadways.
Having now described the nature of my said Invention, and the
system,. mode, or manner in or under which the same is or may be

page_text: used or practically carried into effect, I would observe in conclusion
that what I consider novel and original, and therefore claim as the
Invention secured to me by the herein-before in part recited Letters
Patent is,-
First. The constructing of roads or other surfaces for traffic of loose
or broken stones, or partly of paving setts and partly of loose or broken
stones, or other suitable material, placed upon prepared ground and
grouted together with a fluid mixture or grout, as herein-before described
and shewn at Figures 1 and 7 of the annexed Drawings.
Second. The arrangement and construction of apparatus illustrated at
Figures 2, 3, 4, 5, and 6 of the accompanying Drawings, or any merc
modification thereof, wherein the fluid mixture or grout is commingled,
and whereby the said grout is distributed over the surface of the road or
other surface for traffic being constructed, as herein-before set forth.
In witness whereof, I, the said David Crawford Proudfoot, have
hereunto set my hand and scal, this Twenty-ninth day of
September One thousand eight hundred and seventy-one.
DAVID CRAWFORD PROUDFOOT. (L.S.)