AN IMPROVED PAVEMENT."
Year: 1870

page_text: LETTERS PATENT to Charles Pinnington, of St. James' Terrace,
Caledonian Road, in the County of Middlesex, for the Invention of
"AN IMPROVED PAVEMENT."
PROVISIONAL SPECIFICATION left by the said Charles Pinnington at
the Office of the Commissioners of Patents, with his Petition, on
the 20th August 1870.
I, CHARLES PINNINGTON, of St. James' Terrace, Caledonian Road, in
the County of Middlesex, do hereby declare the nature of the said
Invention for "AN IMPROVED PAVEMENT," to be as follows :-
My said Invention relates to a compound pavement, which is chiefly
designed for roads and other ways or thoroughfares, but which may
also be used for covering yards, gateways, the floors of stables, and for
other like purposes.
The said pavement is durable, elastic to the
tread, impervious to moisture, greatly less noisy than ordinary stone
pavements, economical of construction, and easy of repair.

page_text: The said pavement is laid in the following manner :— -I first excavate
and level the subsoil to a depth of about seventeen inches. I then lay
upon the surface so prepared a bed or layer of mixed coal tar and
sawdust for a depth of about six inches. Over this substance I then
place boards or slabs of wood, which are laid diagonally or obliquely
upon the bed or layer of tar and sawdust in such a manner as to com-
pletely cover the same. These boards or slabs are dipped into or
otherwise coated with tar before laying them down. Over this first
layer or thickness of wood I place another layer consisting of similar
boards or slabs, but laid transversely across the first layer of wood, so
that cach board or slab of the upper layer will cross and rest upon a
number of the lower boards or slabs, and thus bind the whole together in
every part. I prefer to use deal boards or slabs about three feet long,
eight inches wide, and one and a quarter inch in thickness, but boards
or slabs of other wood may be used, and they may be of any desired or
convenient length, breadth, and thickness. Upon the foundation thus
prepared I then place a paving composed of granite or other suitably
hard stone. I prefer to use this stone in blocks about four inches*square
by seven inches in depth. The particular size however is not material
so long as the blocks are uniformly of one depth throughout the work.
Great care must be taken to ensure this uniformity of depth, and each
block must be supported vertically with its base resting upon the upper
layer of the wood flooring, so that the upper surface of the pavement
shall be smooth and perfectly free from any inequalities throughout
its entire area. The stones being in small blocks will have many inter-
sections or interstices crossing each other throughout the surface, which
will present a good foothold for the animals and prevent their slipping
either forward or to one side, while at the same time the general level of
the surface is not broken or impaired by projections or hollows. In
laying down these blocks of stone they are set in a mixture of tar and
sand or other substance impervious to or not containing water. After
the stone paving has been thus laid I pour over it boiling tar and cover
the same with sand. The tar and sand will work down between the
blocks of stone and will render the pavement a compact mass. If
necessary I may then pass a heavy roller over the surface. The com-
pound pavement thus formed having a perfectly uniform upper or
working surface of hard stone supported on an elastic bed or foundation
will have its materials arranged in the most advantageous manner to
ensure their durability. The stone blocks being in small pieces will not

page_text: only present a sure foothold for the horses, but by reason of the
smoothness of their surface and the manner in which the foundation is
constructed will greatly diminish the noise produced by the traffic. The
pavement, moreover, being rendered perfectly impervious to moisture by
the boiled tar and sand will not allow any water or other liquid to
penetrate to the wood flooring, and the durability of the pavement will
be thereby still further ensured.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Charles Pinnington in the Great Seal Patent Office
on the 21st December 1870.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, CHARLES
PINNINGTON, of St. James's Terrace, Caledonian Road, in the County of
Middlesex, send greeting.
'
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of August, in the year
of our Lord One thousand eight hundred and seventy, in the thirty-
fourth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Charles Pinnington; Her special licence
that I, the said Charles Pinnington, my executors, administrators, and
assigns, or such others as I, the said Charles Pinnington, 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 "AN IMPROVED PAVEMENT,'
upon the condition (amongst others) that I, the said Charles Pinnington,
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.
ور
KNOW NOW YE, that I, the said Charles Pinnington, 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

page_text: by the following statement, reference being had to the accompanying
Drawing forming a part of this Specification.
My said Invention relates to a compound pavement which is chiefly
designed for roads and other ways or thoroughfares, but which may also
be used for covering yards, gateways, the floors of stables, and for other
like purposes. The said pavement is durable, elastic to the tread,
impervious to moisture, considerably less noisy than ordinary stone
pavements, economical of construction, and easy of repair.
My improved pavement is laid in the following manner:- -I first
excavate and level the subsoil to a depth of about seventeen inches, I.
then lay upon the surface so prepared a bed or layer of mixed unboiled
coal tar and sawdust for a depth usually of about six inches. Tar when
raw or unboiled will remain in a soft condition, and therefore this
mixture of tar and sawdust will not become hard and rigid.
By this
means I obtain at a slight cost a bed, which is at the same time both.
elastic and durable. Other substances somewhat analogous to tar might
be substituted therefor, but I know of no material which will so well
answer the purpose of my Invention. Over this elastic bed I then place
boards or slabs of wood, which are laid diagonally or obliquely upon the
bed or layer of tar and sawdust in such a manner as to completely cover
the same. These boards or slabs are dipped into or otherwise coated
with tar before laying them down. Over this first layer or thickness of
wood I place another layer consisting of similar boards or slabs laid
transversely across the first layer of wood, so that each board or slab of
the upper layer will cross and rest upon a number of the lower boards or
slabs, and thus bind the whole together in every part. Each board or
plank of the top layer must be so laid upon those of the under layer that
the ends of each top board will be midway or nearly so between the two
ends of the bottom boards, so that the top boards will be firmly and
evenly supported upon a base equal to the entire length of the bottom
boards. I prefer to use deal boards or slabs about three feet long, eight
inches wide, and one and a quarter inch in thickness, but boards or
slabs of other wood may be used and they may be of any desired or
convenient length, breadth, and thickness. Upon the foundation thus
prepared I then place a paving composed of granite or other suitably
hard stone. I prefer to use this stone in blocks about four inches
square by seven inches in depth. The particular size however is not
material so long as the blocks are uniformly of one depth throughout

page_text: the work. Great care must be taken to ensure this uniformity of depth
and each block must be supported with its base resting upon the upper:
layer of wood flooring, so that the upper surface of the pavement shall
be free from any inequalities throughout its entire area. The stone
being in small blocks will present many intersections or interstices
crossing each other at every part of its surface, which will form a good
foothold for the animals, and prevent their slipping either forward or to
one side, while at the same time the general level of the surface is not
broken or impaired by projections or depressions. In laying down these
blocks of stone they are set in a mixture of tar and sand, or other
substance not containing water and impervious to moisture. After the
stone paving has been thus laid I pour over it boiling tar (or tar which
has been boiled) and cover the same with sand. Tar in this condition.
is altogether different from the raw or unboiled tar with regard to its
capability of hardening, as the boiled tar will quickly set or become
hard. Sand also has certain peculiar properties which I have found
make it particularly advantageous when applied to my pavement, and
when it is laid on or mixed with the boiled tar the tar and sand together
will work down between the blocks, and will render the pavement a
compact mass. If necessary I may then pass a heavy roller over the
surface
Figure 1 is a plan or a piece of my improved pavement showing parts.
of the same in various stages of completion.
Figure 2 is a transverse section on the line x, x, Figure 1. Like
Ictters indicate the same parts in both Figures.
A is the clastic bed or cushion which as herein-before stated is formed
of a mixture of unboiled tar and sawdust. The depth of this bed may be
varied according to the nature of the soil; for instance, in forming a
road over clay or gravel a depth of six or seven inches would be quite
sufficient, whereas on sand the depth of the elastic bed might be
advantageously increased to nine inches. B indicates the first layer of
wooden slabs, planks, or boards, as herein-before stated, I prefer to lay
these boards obliquely to the direction of the road and they must extend
over the entire surface of the elastic bed or cushion A, which being
slightly plastic will allow the said boards to bed themselves evenly and
solidly thereon. C is the second or upper layer of boards or planks,

page_text: which are laid across the boards B at or nearly at a right angle thereto,
as shewn. In laying this wood flooring it is very important to make
sure that the ends C₁ of each board C are placed midway or nearly so,
between the ends B' of the lower boards B, so that each board C shall be
supported without a capability of tilting under a heavy load, as might
happen if the flooring were laid without any regard to the relative
positions of the upper and lower boards or slabs. The importance of the
proper arrangement of the boards or slabs will be more clearly under-
stood by taking into consideration the fact that a very heavy weight
might at any time be entirely sustained by the surface immediately over
the end of any one of the boards C, and if that particular board crossed
the bottom board B at one of its ends B¹ the bed or cushion A might
give way sufficiently to cause the said board to tilt and thereby cause
serious disarrangement of the pavement.
If the bed or cushion A were made of some hard rigid or unyielding
substance, the danger of such tilting of the boards might be less than
when an elastic bed is used, and therefore such care in laying. the boards
would not be necessary, but then the advantage obtained by my
Invention with regard to the elasticity and comparative noiselessness of
the pavement would be sacrificed. When however this yielding or
elastic bed or cushion has the boards or planks composing the wood
flooring placed thercon one over the other in the particular manner
described each stone of the pavement is sustained by a large base or
area of surface on the clastic bed, and I thus obtain such a support for
the said flooring as will always keep the upper surface of the pavement
uniformly intact, while I avoid the extreme rigidity or want of elasticity
which is so unpleasantly conspicuous in ordinary stone pavements. . D is
the stone paving which as shewn is composed of small blocks, the
base of each block resting upon the wood flooring. These blocks are
shown about four inches square, by about seven inches deep, which
dimensions I have found to be convenient in practice.
It will be scen
that the interstices or intersections formed by these small stones will
afford a good foothold for animals without impairing the general
uniformity or smoothness of the surface. This pavement would be firm
and durable without the covering of mixed sand and tar, but it is
preferable to have this covering applied as herein-before set forth.
The compound pavement thus formed having a perfectly uniform
upper or working surface of hard stone supported on an clastic bed or

page_text: One
foundation will have its materials arranged in the most advantageous
manner to ensure the durability of all parts of the pavement.
great cause of the rapid destruction of stone pavements, namely, the
infiltration of liquid from the surface is entirely prevented by the boiled
tar and sand applied to the stonework. The stone blocks being in small
pieces, will not only present a sure foothold for the horses, but by reason
of the smoothness of their surface, and the manner in which the
foundation is constructed will be almost noiseless under the traffic.
Having thus fully described my said Invention and shewn how the
same may be conveniently and advantageously carried into practice I
wish it understood that I claim,--
First. A compound pavement consisting of the elastic bed of unboiled
tar and sawdust or other materials possessing similar properties, the two
layers of wood slabs or boards crossing each other with the blocks of
stone resting upon the top layer of wood and with or without the covering
of sand and boiled tar, substantially as herein set forth.
Second. Two layers of wooden slabs or boards arranged crosswise or
obliquely one over the other, with the blocks of stone resting upon
the top layer, substantially as set forth for the purpose specified...
In witness whereof, I, the said Charles Pinnington, have hereunto
set my hand and seal, this Nineteenth day of December, in
the year of our Lord One thousand eight hundred and seventy.
CHARLES PINNINGTON. (L.S.)
Witness,
W.ROB. LAKE.