IMPROVEMENts in the ConstrUCTION OF PAVEMENTS FOR ROADWAYS AND 'FOR OTHER LIKE PURPOSES
Year: 1874

page_text: LETTERS PATENT to Philip Zadig, of San Francisco, in the State of
California, one of the United States of America, for the Invention
of "IMPROVEMENts in the ConstrUCTION OF PAVEMENTS FOR ROADWAYS AND
'FOR OTHER LIKE PURPOSES."
Sealed the 2nd October 1874, and dated the 6th August 1874.
COMPLETE SPECIFICATION filed by the said Philip Zadig at the Office
of the Commissioners of Patents, with his Petition and Declaration,
on the 6th August 1874, pursuant to the 9th Section of the Patent
Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, PHILIP
ZADIG, of San Francisco, in the State of California, one of the United
States of America, send greeting.
WHEREAS I am in possession of an Invention for "IMPROVEMENTS IN
THE CONSTRUCTION OF PAVEMENTS FOR ROADWAYS AND FOR OTHER LIKE PURPOSES,"
and have petitioned Her Majesty to grant unto me, my executors,
administrators, and assigns, Her Royal Letters Patent for the same, and
have made solemn Declaration that I am the true and first Inventor
thereof.

page_text: Figure 1. represents an clevation of the said flask with part broken :
away; Figure 2 is a plan of the said flask; Figure 3 is a plan of one
side of the said flask; Figure 4 is an elovation of the aforesaid block in
an inverted position; Figure 5 is a plan or top view of the said block.
In the building up of my paving block I prefer to construct it broader:
at the top than at the base, and for holding the cobbles in position
while the block is being prepared I have devised special means con-
sisting of a flask or form A having a removable base B provided with a
raised centre, around which centre the sides of the flask fit closely. Two
of these sides C which forin the compartment are entire, while the
adjoining two aro divided vertically to the base plate, as shown, and aro:
made with tongues and grooves C' so that the sides of the flask can bo
casily removed and leave the composition or concrete of which the
paving block is formed upon the raised portion B₁ of the base plate;
these divisions are kept in place by clamps or hooks and cycs D attached
to the sides and base plate of the flask.
The flasks I construct of wood lined with zinc plates, the four sides
being about 4 inches high or of a height sufficient to hold the.cobbles
when in position a little above the point of the largest swell or cir-:
cumference. The interior surfaces are coated with a weak solution of
lime applied with a brush before filling.

page_text: In operation the sides of the form being closed and resting upon the
baso I fill the space with cobble stones set on end and packed closely so
that no lateral movement of the stones is had, after which dry sand is
scattered over the cobbles which naturally falls down and fills the spaces
between to a depth of about one-fourth of an inch from the bottom of
the flask up. In this position a cement of asphalt and gravel with
fifteen per cent. of lime to impart toughness is tempered with coal tar or
other materials usually employed to retain the adhesive properties of the
asphalt and prevent the rays of the sun from affecting the block when
laid. This cement is poured upon the cobbles and fills the spaces
between and builds up the block to the desired height or thickness
completely surrounding the cobble stones and coating the tops. In this
position, and as soon as cooled, I strike off the sides of the flask, allowing
the block to remain upon the base or bed plate, and cover the entire
upper or exposed surface with bricks or tiles E which are first dipt in
hot asphaltum and applied to the block so as to be partially embedded
in it.
The tiles or bricks may be of inferior quality but are set firmly in
asphalt or cement and should project on all sides. about % of an inch,
so that when laid a space of about two inches is had for a base or foun-
dation for a sand and gravel packing, which I employ to fill the joints
and keep the blocks in position when placed along the roadway.
The blocks being firmly set and formed in the flasks and the road bed
having been properly prepared with the usual crown, and the whole
battered down with a maul so as to render the foundation as compact as
possible, the blocks are transported to the place where they are to be
employed, and inverted or turned bottom up and placed in position so as
to break joints and leave spaces, as above, described, between the sides
and ends of about two inches, which spaces are filled with asphalt and
gravel up to the top, which binds the blocks together laterally in a strong
bond.
It will here be observed that the unequal projections of the cobbles of
the block upon its base are embedded in asphalt resting upon a plain or
flat surface of brick or tile, while the upper surface of the block will be
composed of bare or uncovered points upon a plane.
If the pavement be found objectionable on account of the liability of
animals to slip, the surfaces of the blocks may be corrugated or provided

page_text: with furrows; this is accomplished by corrugating the base plate of the
flask so as to form ridges and depressions of about one-fourth of an inch
high and two and one half inchies wide from above the horizontal plane
of the block when laid.
The blocks may be constructed in a variety of shapes for crossings,
gutters, and tramways.
In the construction of my pavement nothing is relied upon for the
adhesiveness of the asphaltum to the cobble stones, but much depends
upon embedding the cobbles or stones in a material which is immovable
in itself and which has become compact when set or cooled, rendering
the cobbles immovable upon a solid foundation and the upper part or
surface smooth and elastic. By these means the objection to the use of
cobble stones for paving streets by reason of their upwardly projecting
points and their liability to being moved about by heavy traffic is over-
come and the paving block made firm, durable, and impervious to water
and the effects of the atmosphere.
Having thus fully described my said Invention, and the manner of
performing the same, I wish it understood that I claim,―
First. A paving block composed of cobble stones or broken stones
with a brick or tile foundation E when constructed and built up, sub-
stantially in the manner and of the materials above set forth.
Second. The flask or form A provided with removable sides C,
base B, and clamps D, substantially as and for the purposes specified.
In witness whereof, I, the said Philip Zadig, have hereunto set
my hand and seal, this Ninth day of July, in the year of our
Lord One thousand eight hundred and seventy-four.
A