IMPROVEMENTS IN ROAD PAVING
Year: 1873

page_text: LETTERS PATENT to Henry Henson Henson, of No. 24, Lawrence
Pountney Lane, in the City of London, Civil Engineer, for the
Invention of "IMPROVEMENTS IN ROAD PAVING."
PROVISIONAL SPECIFICATION left by the said Henry Henson Henson
at the Office of the Commissioners of Patents, with his Petition,
on the 26th May 1873.
I, HENRY HENSON HENSON, of No. 24, Lawrence Pountney Lane, in
the City of London, Civil Engineer, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN ROAD PAVING," to be as follows:-
This Invention relates to the construction of road paving in such a
manner as to secure a sound and durable waterproof surface for traffic,
free from slipperyness, mud, and noise.
In order to provide a sound foundation for the roadway I proceed
according to the following methods :-
:-
When the road is already paved with stone blocks, which are usually
Jaid on their edges, I remove these blocks, and after rendering the surface

page_text: of the ground even I relay as many of the blocks on their flat sides as
are necessary to cover the road. I then fill in the joints between the
stones and cover their surface with artificial or natural asphalt or cheap
bituminous compound of like character evened down to the form required
for the reception of the upper paving.
For the foundation of a road that is not already paved I proceed in a
similar manner, covering the even surface of the ground with stone
blocks laid on their flat sides and cementing and rendering them even by
bituminous material. The foundation being thus prepared may receive
an upper paving of any known kind, whether of wood, stone, asphalt,
or combinations of such materials.
I prefer, however, to construct the upper paving in the following
manner-On the prepared foundation I lay stone blocks, which are
worked tolerably flat on their upper and lower surfaces, but are left rough
round their edges. These blocks may be laid close together, but prefer-
ably with spaces between them, and with the joints either parallel and
transverse or diagonal to the line of road. The joints between the blocks
are then filled in with natural or artificial asphalt or similar bituminous
material, so that the roadway presents a compound surface partly stone
and partly asphalt, which, while it is waterproof and durable is smooth
and free from mud and slipperyness. As the freedom from slipperyness
depends in great measure upon presenting materials of different degrees
of hardness on the upper surface of the road I sometimes place
preserved wood blocks endways of the grain between the stone blocks,
and then cement the whole by bituminous material as above described.
The wood thus laid may either be of such depth as to project a little
above the surface of the stone blocks or it may be a little below that
surface, in which case I fill in the hollows between the stones with a
compound of gravel and tar or other bituminous material.
.
Sometimes, instead of employing wood to interspace the stones I
employ iron blocks grooved on the upper surface, as in this case the
iron does not require to have the same depth as the stone, but may.
preferably be of about half the depth; after placing the stone blocks I
fill in the grooves between them to about half their depth with a coarse
mortar-like compound of asphalt, with sand and gravel, on which I
place the shallow blocks of iron, and then cement the whole as described
above.

page_text: Instead of employing a stone foundation for the roadway I sometimes
use wood in the following manner :-After rendering the ground even I
lay thereon planks or battens of preserved wood, which may be secured
by trenails on sleepers previously laid down, so as to present a floor
resembling the deck of a ship. I fill the jointings of the timber and
render its surface water-tight by serving it with tar, pitch, asphalt, or
other bituminous matter, and on the foundation thus prepared I lay the
paving of stone blocks with bituminous jointing or interspaced with
wood or iron as described above. When such a wood foundation is
employed its surface may be divided into cells or compartments by fillets
of preserved wood nailed or pinned to the planking, and in each of these
cells is laid one of the stone blocks, which is thereby steadied in its
place, and the spaces between these blocks are then filled in as above
described.
Instead of employing stone blocks for the upper paving I sometimes
use blocks of asphalte, in which are inserted pieces of cane presenting
their ends to the traffic surface so as to diminish the slippery character
of such paving. These compound blocks of asphalt and cane may be
laid on either the stone or the wood foundation above described, either
close together or interspaced with wood or iron, or they may be inter-
spaced with stone, the joints being made good with bituminous cement
as described with reference to the stone blocks.
It is obvious that according to the methods above set forth for
constructing the foundation and the traffic surface of a roadway the
lines of jointing of the latter may be arranged in any desired directions,
and farther, that different portions of the roadway may be formed in
different ways, so as to suit the special traffic on such portions. Thus
the roadway may to a certain extent be made equivalent to a tramway
by laying two or more lines of smooth asphalt paving to form wheel
tracks for vehicles, with the spaces between the tracks paved in the
manner above described to give hold for the feet of horses.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Henson Henson in the Great Seal Patent
Office on the 20th November 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
HENSON HENSON, of No. 24, Lawrence Pountney Lane, in the City of
London, Civil Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-sixth day of May, in the year of our
Lord One thousand eight hundred and seventy-three, in the thirty-sixth
year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Henry Henson Henson, Her special license
that I, the said Henry Henson Henson, my executors, administrators,
and assigns, or such others as I, the said Henry Henson Henson, 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 "Iм-
PROVEMENTS IN ROAD PAVING," upon the condition (amongst others) that I,
the said Henry Henson Henson, 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 Inven-
tion, 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 Henry Henson Henson, do hereby
declare the nature of the 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, that is to say :—
This Invention relates to the construction of road paving in such a
manner as to secure a sound and durable waterproof surface for traffic
free from slipperyness, mud, and noise.
In order to provide a sound foundation for the roadway I proceed
according to the following methods :-
When the road is already paved with stone blocks, which are usually
laid on their edges, I remove these blocks, and after rendering the surface

page_text: of the ground even I relay as many of the blocks on their flat sides as
are necessary to cover the road. I then fill in the joints between the
stones and cover their surface with artificial or natural asphalt or cheap
bituminous compound of like character, evened down to the form required
for the reception of the upper paving.
For the foundation of a road that is not already paved I proceed in a
similar manner, covering the evened surface of the ground with stone
blocks laid on their flat sides or flags, and cementing and rendering them
even by bituminous material. Although I prefer laying stones for the
foundation on their flat sides they may obviously be placed on their
edges, but in that case a greater quantity of material would be necessary
to cover the surface, and soil would have to be removed to allow for the
additional depth of the upper layer. The foundation being thus prepared,
may receive an upper paving of any known kind, whether of wood,
stone, asphalt, or combinations of such materials.
1
I prefer, however, to construct the upper paving in the following
manner: On this prepared foundation I lay stone blocks, which are
worked tolerably flat on their upper and lower surfaces, but are left
rough round their edges. These blocks may be laid close together, but
preferably with spaces between them, and with the joints either parallel
and transverse or diagonal to the line of road. The joints between the
blocks are then filled in with natural or artificial asphalt or similar
bituminous material, so that the roadway presents a compound surface,
partly stone and partly asphalt, which, while it is waterproof and
durable is smooth and free from mud and slipperyness. As the freedom
from slipperyness depends in great measure upon presenting materials
of different degrees of hardness on the upper surface of the road I
sometimes place preserved wood blocks endways of the grain between the
stone blocks and then cement the whole by bituminous material as
above described. The wood thus laid may either be of such depth as to
project a little above the surface of the stone blocks, or it may be a little
below that surface, in which case I fill in the hollows between the stones
with a compound of gravel and tar or other bituminous material.
Sometimes, instead of employing wood to interspace the stones I
employ iron blocks grooved on the upper surface, as in this case tho
iron does not require to have the same depth as the stone, but may
preferably be of about half the depth; after placing the stone blocks I

page_text: fill in the grooves between them to about half their depth with a coarse
mortar-like compound of asphalt with sand and gravel, on which I place
the shallow blocks of iron and then cement the whole as described above.
Both wood and iron blocks may be used to interspace the stone blocks,
as in this way is obtained a surface having various degrees of hardness.
Instead of employing a stone foundation for the roadway I sometimes
use wood in the following manner :-After rendering the ground even I
lay thereon planks or battens of preserved wood, which may be secured
by trenails on sleepers previously laid down, so as to present a floor
resembling the deck of a ship. I fill the jointings of the timber and
render its surface watertight by serving it with tar, pitch, asphalte, or
other bituminous matter, and on the foundation thus prepared I lay the
paving of stone blocks with bituminous jointing, or interspaced with
wood or iron as described above. When such a wood foundation is
employed its surface may be divided into cells or compartments by fillets
of preserved wood nailed or pinned to the planking, and in each of these
cells is laid one of the stone or other blocks, which is thereby steadied in
its place, and the spaces between these blocks are then filled in as above
described.
Instead of employing stone blocks for the upper paving I sometimes
use blocks of asphalt, in which are inserted pieces of cane presenting
their ends to the traffic surface so as to diminish the slippery character
of such paving. Such blocks may be prepared by forming the asphalt
in a fused or partly fused condition in a mould made to the size and
shape desired, and inserting the pieces of cane into the asphalt before it
sets. These compound blocks of asphalt and cane may be laid on either
the stone or the wood foundation above described, either close together
or interspaced with wood or iron, or they may be interspaced with stone,
the joints being made good with bituminous cement as described with
reference to the stone blocks.
It is obvious that according to the methods above set forth for con-
structing the foundation and the traffic surface of a roadway, the lines
of jointing of the latter may be arranged in any desired directions, and
farther, that different portions of the roadway may be formed in different
ways so as to suit the special traffic on such portions. Thus the roadway
may, to a certain extent, be made equivalent to a tramway by laying two
or more lines of smooth asphalt paving to form wheel tracks for vehicles,

page_text: with the spaces between the tracks paved in the manner above described
to give hold for the feet of horses.
Having thus described the nature of my Invention and in what
manner the same is to be performed, I claim,—
First. Constructing a foundation for a roadway of stone cemented and
rendered even by asphalt or other bituminous material, substantially as
herein described.
Second. Constructing a roadway in two layers, the lower layer being a
foundation such as is referred to in the preceding claim, and the upper
layer consisting of blocks of stone, of wood, or of iron, or of blocks of
these different kinds interspacing each other, having between them
intervals filled in with asphalt or other bituminous material substantially
in the manner and for the purposes herein set forth.
Third. The use in the upper layer of a roadway of paving blocks
compounded of asphalt with pieces of cane inserted therein, substantially
as herein described.
In witness whereof, I, the said Henry Henson Henson, have hereunto
set my hand and seal, this Nineteenth day of November, in the
year of our Lord One thousand eight hundred and seventy-three.