IMPROVEMENTS IN PAVING AND ASPHALTING ROADS, STREETS, AND FOOTWAYS, AND IN THE COMPOSITION EMPLOYED THEREFOR
Year: 1871

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of
"IMPROVEMENTS IN PAVING AND ASPHALTING ROADS, STREETS, AND FOOTWAYS,
AND IN THE COMPOSITION EMPLOYED THEREFOR."-A communication from
abroad by Charles Felix Sebille, of Paris, in the Republic of France.
Sealed the 26th April 1872, and dated the 30th October 1871.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson at
the Office of the Commissioners of Patents, with his Petition, on
the 30th October 1871.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County
of Middlesex, Gentleman, do hereby declare the nature of the said Inven-
tion for "IMPROVEMENTS IN PAVING AND ASPHALTING ROADS, STREETS, AND FOOT-
WAYS, AND IN THE COMPOSITION EMPLOYED THEREFOR," a communication from
abroad by Charles Felix Sebille, of Paris, in the Republic of France, to
be as follows:-
This Invention relates to the production of a composition which may
be employed either solid in the form of blocks for paving purposes, or
applied in a heated plastic condition to the surface of roads and footways

page_text: in lieu of ordinary asphalte. This composition consists of the following
materials in or about the proportions given, which may be varied more
or less, viz., slate refuse in a pulverized condition, ten per cent.; natural
Seyssel, or asphalte of Auvergne, Switzerland, or other source of supply,
fifteen per cent.; limestone or Paris white (blanc de Meudon) in powder,
fifty-eight per cent.; bitumen purified or refined by the well-known pro-
cesses of Sebille and Durand, 15.700 per cent.; a solid greasy or fatty
matter such as tallow, suet, and the like 0·300 per cent. These materials
are well mixed or incorporated together, and are heated so as to form a
paste which is run into moulds of a cubical or other shape so as to
form paving blocks, which may be employed in a similar manner to the
ordinary granite stones; or the paste may be applied in a heated state to
the surface of roads and footways like ordinary asphalte, and of sufficient
thickness to withstand the traffic to which it is to be subjected. This
composition being rich in refined bitumen is of course more expensive
than ordinary bitumen, and in order to reduce it to a medium price in its
application to roads subjected to heavy traffic where a layer exceeding
one and a quarter inches in thickness is employed, it is proposed to pre-
pare a surface or foundation by first depositing on the ground a layer
composed of sand and pebbles combined with gas tar or mineral pitch.
Before this is quite cool the improved composition is spread. The same
system is to be adopted when using the composition in the form of paving
blocks, the foundation which is placed on the soil being composed of sand,
pebbles, and gas tar agglomerated in a mass, which becomes as it were
welded or soldered to the paving blocks of the improved composition.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Henry Johnson in the Great Seal Patent
Office on the 30th April 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of Middlesex,, 3
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirtieth day of October, in the year of
our Lord One thousand eight hundred and seventy-one, in the thirty-
fifth year of Her reign, did, for Herself, Her heirs and successors, give 3

page_text: and grant unto me, the said John Henry Johnson, Her special licenco
that I, the said John Henry Johnson, my executors, administrators, and
assigns, or such others as I, the said John Henry Johnson, 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 time 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 PAVING AND
ASPHALTING ROADS, STREETS, AND FOOTWAYS, AND IN THE COMPOSITION EMPLOYED
THEREFOR,' a communication to me from abroad by Charles Felix
Sebille, of Paris, in the Republic of France, upon the condition (amongst
others) that I, the said John Henry Johnson, my executors or adminis-
trators, by an instrument in writing under my, or their, or one of their
hands and scals, 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 Henry Johnson, 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 :-
This Invention relates to the production of a composition which may
be employed either solid in the form of blocks for paving purposes or
applied in a heated plastic condition to the surface of roads and footways
in lieu of ordinary asphalte.
This composition consists of the following materials in or about the
proportions given, which may be varied more or less, viz.: slate refusé
in a pulverized condition, ten per cent."; natural Seyssel or asphalte of
Auvergne, Switzerland, or other source of supply, fifteen per cent:; lime-
stone or Paris white (blanc de Meudon) in powder, fifty-eight per cent. ;
Bitumen, purified or refined by the well-known processes of Sebille and
Durand, 15-700 per cent.; a solid, greasy, or fatty matter such as tallow,
suet, and the like 0.300 per cent. This composition is herein-after
6 termed schisto-asphaltic. These materials are well mixed or incorporated
together, and are heated so as to form a paste which is run into moulds
of a cubical or other shape so as to form paving blocks, which may be
employed in a similar manner to the ordinary granite stones. Or the

page_text: paste may be applied in a heated state to the surface of roads and foot-
ways like ordinary asphalte, and of sufficient thickness to withstand the
the traffic to which it is to be subjected.
This composition being rich in refined bitumen is of course more
expensive than ordinary bitumen, and in order to reduce it to a medium
price in its application to roads subjected to heavy traffic, where a layer
exceeding one and a quarter inches in thickness is employed, it is pro-
posed to prepare a surface or foundation by first depositing on the
ground a layer composed of sand and pebbles combined with gas
tar or
mineral pitch, which composition is herein-after termed " bituminous
beton." Before this is quite cool the schisto-asphaltic composition is
spread. The same system is to be adopted when using the composition
in the form of paving blocks, the foundation which is placed on the soil
being composed of sand, pebbles, and gas tar agglomerated in a mass
which becomes as it were welded or soldered to the paving blocks of the
improved composition.
The paving blocks are made in moulds and are composed as follows:
Firstly, head of paving block "schisto-asphaltic" compound. The
materials which enter into its composition are wastes, generally taken
from slate quarries and mines of schist, and which are pulverized natural
asphalte crushed, or, in lieu thereof, argillaceous earth dried and crushed,
chalk in powder, natural bitumen of La Trinité, or derived from any
other source, the whole heated and mixed in about the following pro-
portions:-
Schist from slate quarries pulverized, say 35
per cent.
Asphalte or clay
Chalk or calcareous material
Natural bitumen
Tallow or other fatty matter
-
10
"3
"
-
38
""
"
-
16-700
دو
-
0-300
د,
"
"
total 100 parts.
For certain mosaics one or other of the following compositions may a
be used to obtain paving of different colors :-
White Color.-Calcareous material, chalk, or white stone 84 per cent.

page_text: when they are laid in lime. This combination also permits their being
sent to the colonies or elsewhere as ballast, as they are no longer liable
to contract or warp even under the influence of tropical heat.
The cylindrical paving block shown, Fig. 4, having schisto-asphaltic
material top and bottom, as indicated by A, the intermediate part being
composed of bituminous beton, as indicated by B, may be turned when
the part exposed to the traffic has been sufficiently worn.
The system of paving shown, Figures 5 and 6, offers the advantage of
perfect unity, and of avoiding the partial repair usually necessitated after
cach new paving, because the foundation not being perfectly even every-
where some of the blocks in yielding under the weight of the carriages
enter the earth and form cavities, which cannot occur with the conical
blocks laid as shown, Figures 5 and 6, inasmuch as the pavement forms,
so to say, an arch, that is to say, each block supports the load by reason
of the pressure of each block against the other.
The form of paving shown, Figures 7 and 8, will be found very
advantageous in distributing the weight of the traffic amongst the
blocks and preventing any partial upheaving. No. 1, Fig. 7, indicates a
block with "schisto-asphaltic" only on the upper surface, whereas Nos. 2
and 3 have it both top and bottom, so that they may when worn be
turned without other manipulation than the mere relaying.
As the mixing or kneading and the moulding of the paving blocks
may be effected with the same tools and in the same manner as the
manufacture of bricks from clay, it will be at once understood that
these paving blocks cannot be very costly, and may easily compete with
ordinary paving stones and the material of ordinary asphalted ways.
The proportions above given are all approximative, and will necessarily
vary with the quality of the materials and the particular application in
view.
Advantages of this schisto-asphaltic paving :-Firstly, the noise of the 3
carriages is considerably lessened; secondly, there is very little mud;
thirdly, the cost is less than that of asphalted ways, of which it possesses
the merits without the disadvantages, particularly as regards repair.
The paving blocks not being liable to be crushed under the weight of
the carriages, there remains the wear which will not be greater than that a
of asphalted ways. It will be easy to replace the worn blocks, and to
recoat at the works the head of those removed, so that they may be used
again.

page_text: Having now described and ascertained the nature of the Invention
communicated to me as aforesaid, and in what manner the same is or
may be performed, I would have it understood that the compounds
herein termed the "schisto-asphaltic" and the "bituminous-beton" are
substantially but one composition and the necessary complement of each
other, the one as wearing surface or head of paving or paving block,
the other as foundation or body; and that what I claim as secured to
me by the herein-before in part recited Letters Patent is, the use of this
composition substantially as and for the purposes herein-before set forth.
In witness whereof, I, the said John Henry Johnson, have here-
unto set my hand and seal, this Thirtieth day of April, in the year
of our Lord One thousand eight hundred and seventy-two.