IMPROVEMENTS IN ASPHALTE PAVING
Year: 1873

page_text: LETTERS PATENT to John Knight, of Number 27, Cornhill, in the
City of London, for the Invention of "IMPROVEMENTS IN ASPHALTE
PAVING."
Sealed the 3rd February 1874, and dated the 18th October 1873.
PROVISIONAL SPECIFICATION left by the said John Knight at the
Office of the Commissioners of Patents, with his Petition, on the
18th October 1873.
I, JOHN KNIGHT, of No. 27, Cornhill, in the City of London, do
horeby declare the nature of the said Invention for "IMPROVEMENTS IN
ASPHALTE PAVING," to be as follows:-
The object of my Invention is to remedy one objection which exists to
the use of asphalte for roadways, namely, the want of foothold for the
horses consequent upon the smoothness of the surface.
My Invention is especially applicable to paving made with powdered
asphalte material, but may also be applied to paving made with mastic
asphalte

page_text: I prefer to form the foundation of the roadway of concrete in the
usual manner, I then lay strips of wood or other material that may be
found suitable, preferably of a dovetail or wedge form, with the bases of
such dovetail or wedge-shaped strips downwards, on the surface of the
concrete at convenient distances, say six inches apart, and transversely
(either rectangularly or diagonally) across the road; the depth of the
strips of wood is about equal to the proposed thickness of finished
asphalte paving. They are held at the proper distances apart by any
convenient means until the spaces between them are filled up with the
asphalte material, which is rolled, rammed, or otherwise tightly com-
pressed into such spaces.
The strips of wood may be placed with the fibres vertical or
horizontal, and the traffic over a roadway prepared in this manner will
cause transverse hollows, depressions, or channels, and corresponding
ridges to be formed in such roadway, according as the wood or the
asphalte wears away the quicker, thus giving good foothold for horses.
Instead of strips, dovetail or wedge-shaped blocks may be embedded
in the asphalte, and so arranged as to produce hollows and ridges of any
desired form.
I am aware that it has been attempted to secure foothold for horses
by grooving the surface of the asphalte, but such grooves rapidly fill up
and cease to be of use.
In my improved paving the two substances employed do not wear
down equally, and consequently hollows and ridges. are continually
formed which secure the necessary unevenness in the surface.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Knight in the Great Seal Patent Office on
the 18th April 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
KNIGHT, of 27, Cornhill, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Eighteenth day of October, in the
year of our Lord One thousand eight hundred and seventy-three, in the
{

page_text: thirty-fifth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said John Knight, Her special
licence that I, the said John Knight, executors, administrators, and
assigns, or such others as I, the said John Knight, 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 ASPHALTE PAVING," upon the condition (amongst others) that I, the
said John Knight, 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 John Knight, 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 thereof, reference being had to the accompany-
ing Drawing, that is to say :-
The object of my Invention is to remedy one objection which exists
to the use of asphalte for roadways, namely, the want of foothold for
the horses consequent upon the smoothness of the surface.
My Invention is especially applicable to paving made with powdered
asphalte material, but may also be applied to paving made with mastic
asphalte.
I prefer to form the foundation of the roadway of concrete in the
usual manner, I then lay in the roadway strips of wood, but in some
cases, as will be shewn hereafter, other materials may be employed.
It will be found convenient to make the strips of a dovetail or wedge
form, with the bases of such dovetail or wedge-shaped strips downwards
on the surface of the concrete at convenient distances, say from four to
six inches apart, and transversely (either rectangularly or diagonally)
across the road; the depth of the strips of wood is about equal to the
proposed thickness of finished asphalte paving. They are held at the
proper distances apart by any convenient means, until the spaces.

page_text: -between them are filled up with the asphalte material which is rolled,
rammed, or otherwise tightly compressed into such spaces.
The strips of wood may be placed with the fibres vertical or
horizontal, and the traffic over a roadway prepared in this manner will
cause transverse hollows, depressions, or channels, and corresponding
ridges to be formed in such roadway, according as the wood or other
material or the asphalte wears away the quicker, thus giving good foot-
hold for horses

page_text: strips B, B, so as to form a compact and solid roadway, the tapered or
dovetail form of the strips retaining them firmly in the asphalte.
In some cases I form the said strips with a feather edge at the top,
as by that means the asphalte material may be rolled or rammed more
effectually into the spaces between the strips than when the tops of
such strips are flat, as in that case a portion of the said material.is
liable to be compressed on such flat surface and prevents the proper
action of the roller or other compressing instrument upon the material
between the strips.
Figure 1 shews the pavement as it is finished before the traffic begins
to take effect upon it; Figure 2 shews the same pavement after the
traffic has compressed the asphalte and condensed the upper surface
thereof, such compression and condensation reducing the general thick-
ness of the asphalte. During such reduction of thickness the upper
edges of the strips are worn off by attrition of the grit ground in by
the wheels of the vehicles and of the horses' shoes, and they are
ultimately worn down below the surface of the asphalte so as to form
hollow grooves, as shewn at E, E. This effect takes place when the
strips are of softer material than the asphalte, as they then wear down
faster than the asphalte and the grooves are maintained as shewn, form-
ing good foothold for the horses.
When the strips are made of material harder than or such as wears
away slower than the asphalte, the pavement assumes the form shewn
in dotted lines (Figure 2), in which under the action of the traffic the
strips form projections or ridges and the asphalte depressions or hollows.
I however prefer the arrangement first above described.
The strips may be laid rectangularly or obliquely across the
roadway.

page_text: nature, that it shall wear away under the action of the traffic at a rate
differing from that of the asphalte, so as to cause hollows and ridges to
be formed and maintained in the surface of such roadway, as and for the
purpose described.
Second. The employment of taper or dovetail-shaped strips or blocks
of wood or other suitable materials, arranged; adapted, and applied with
and to asphalte, in the various manners shewn and described, and for
the purposes set forth.
In witness whereof, I, the said John Knight, have hereunto set
my hand and seal, this Eighteenth day of April, in the year of
our Lord One thousand eight hundred and seventy-four.