IMPROVEMENTS IN MAKING ROADS AND WAYS, AND IN COVERING THE FLOORS OF COURt YARDS, BUILDINGS, AND OTHER SIMILAR PLACES
Year: 1849

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, AUGUSTUS
ROEN, of Paris, in the Republic of France, Gentleman, send greeting.
WHEREAS Her present most Excellent Majesty Queen Victoria, by Her
Royal Letters Patent under the Great Seal of Great Britain, bearing date at
Westminster, the First day of August, in the thirteenth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Augustus Roehn, Her especial licence, full power, sole privilege and authority,
that I, the said Augustus Roehn, my exors, adñors, and assigns, and such
others as I, the said Augustus Roehn, my exors, adfors, or assigns, should:
at any time agree with, and no others, from time to time and at all times
during the term of years therein mentioned, should and lawfully might make,
usc, exercise, and vend, within England, Wales, and the Town of Berwick-
upon-Tweed, and in all Her Majesty's Colonies and Plantations abroad, and
in the Islands of Jersey, Guernsey, Alderney, Sark, and Man, an Invention of
"IMPROVEMENTS IN MAKING ROADS AND WAYS, AND IN COVERING THE FLOORS OF COURt
YARDS, BUILDINGS, AND OTHER SIMILAR PLACES," being a communication from a
Foreigner residing abroad; in which said Letters Patent is contained a proviso
obliging me, the said Augustus Roehn, by an instrument in writing under my
band and seal, particularly to describe and ascertain the nature of the said Inven-
tion, and in what manner the same is to be performed, and to cause the same
to be inrolled in Her Majesty's High Court of Chancery within six calendar
months next and immediately after the date of the said in part recited Letters

page_text: Patent, as in and by the same, reference being thereunto had, will more fully
and at large appear.
NOW KNOW YE, that in compliance with the said proviso, I, the said
Augustus Roehn, do hereby declare that the nature of the said Invention, and
the manner in which the same is to be performed, is particularly described
and ascertained in and by the following description thereof (that is to say) :-
This Invention consists in the combination and employment of certain sub-
stances for the purpose of covering the surfaces of roads and ways, and the
floors of court yards, buildings, and other similar places, and consists,―
Firstly, in the production of a hard and durable asphaltic mastic for covering
roads or ways, and which is to be laid down in a solid state, in slabs, instead of
being melted, as is usually the case when asphalte is used. This paving
material is produced by mixing together one hundred and seventy-six pounds
of rock asphalte, fifteen pounds of bastenne or other pitch or tar, and seven
pounds of pyrogenous oil of resin or fixed oil; or by mixing together the
following substances (vizt):-Two hundred and twenty pounds of common
line, grey or hydraulic lime, or other calcareous substance in a state of
powder, one hundred and seventy pounds of refined coal tar, and seven pounds
of pyrogenous or other similar oil. The tar or pitch is to be carefully melted
over father a slow fire, and well mixed with the other substances in the follow-
ing männer: First, the powdered asphalte, lime, or other solid substance, is
to be thrown into the pitch or tar, and the mixture carefully stirred; the oil
is then added, and the whole, is allowed to simmer for a short time. The
above proportions will of course be varied, according to the degree of consis-
tence required and the temperature at which the slabs are laid down. It will
of course bé understood that the object of the oils is to impart toughness to
the material, and render it less liable to break. A quantity of small gravel (say
sixty per cent.) 'may, if thought advisable be mixed with this material before
forming it into blocks or slabs.
The Invention consists, secondly, in certain improved methods of covering
roads or ways with calcareous asphalte rock, either natural or artificial.
These methods will of course vary to some extent, according to the locality in
which the-work is to be carried on, the climate or temperature of the weather,
and the nature of the materials to be obtained, and other contingencies,
without however departing from the principal features of the Invention, or in
any manner affecting the result desired. I will therefore describe various
methods which have been found to answer, merely observing that their employ-
ment must of course be left to the discretion of the operator..

page_text: FIRST IROCESS.. CRITTOTMENT OF THE NATURAL BALTIC ROCK
The road having been properly prepared as regards form and dimensions,
and having been well levelled and beaten down, the following operations are
proceeded with The road is to be covered with a layer of gravel, to the
depth of from one and a half to two inches; this is then to be well watered
and beaten flat, and upon the surface thus prepared is spread a layer of mac-
adamized stones, to a depth of about four inches. About one half of these.
stones is laid on at one time, in order to facilitate the flattening down, after.
which the remaining portion is added. On each layer of stones is laid a.
thin layer of sand, which is watered, in order to drive it into the interstices:
between the stones. A quantity of asphalte stone is broken into pieces of the
size usually employed for macadamizing roads, and varying according to the
thickness at which it is intended to be laid on, some of the pieces being always
of a size about a quarter of aninch thicker than the bituminous layer, in order
to allow for the compression caused by the beating down; for instance, for a
layer of about one inch and three quarters thick, the stones will be broken to
a size of about two inches, one and a half inch, and one inch thick; (that is to
say) the largest shall be about one-sixth of an inch more than the layer of
asphalte; and in order to obtain these stones of the size required, they are
passed through sieves having meshes of a corresponding size. A vessel is
provided capable of containing about two hundred pounds of gas tar, more or
Jess, according to the work to be lone, and the broken asphalte is put into a
basket of wood or iron, and steeped lightly in the gas tar, in order to take
up any dirt that may be on their surface, and to facilitate their adherence
when laid down. These pieces, when taken from the large vessel, are
shaken up in the basket, in order that they may be uniformly, although.
slightly, covered with oil, after which they are put into a vessel having a false-
bottom, either perforated with small holes, or made of wire gauze, or a grating..
in order to allow the oil to drain off; and when the pieces of asphalte are suffi-.
ciently dry they may be laid by for use, or laid down immediately. The road
having been prepared, as above described, two straight pieces of wood or other
suitable material, about one sixth of an inch lower than the largest of the
pieces of asphalte employed, are laid down parallel to each other, and the
stones are thrown down between them with a shovel, and made to lie as close as
possible, and cover the two straight pieces. The stones are then beaten or rolled
(the latter I prefer, as being less expensive), until perfectly level and compact,
care being taken not to allow the horses to pass over the surface after it has
been prepared. The interstices between the stones are then to be filled up,

page_text: for which purpose a mastic is employed of a more yielding nature than the
asphaltic rock, in order that it may, by reason of its elasticity, furnish a hold
for the horses' feet, and maintain its consistency at any temperature.
Elastic Mastic.-This elastic mastic is composed of the following ingre-
dients, (viz) twenty-two pounds of mineral bastenne pitch, or coal tar pitch,
or other analogous substance, sixty-six pounds of pyrogenous oil of resin, or
any analogous fatty oils, not affected by frost. Six hundred and eighty-
six pounds of natural asphalte rock, reduced to powder, and two hundred
and six pounds of small gravel, of as calcareous a nature as possible,
making altogether nine hundred and eighty pounds. If any calcareous sub-
stance, such as chalk, lime, ragstone, &c., be employed instead of asphalte,
the following proportions, or thereabouts, must be observed (vizt):--Six hundred
and eight six pounds of lime, chalk, &c., eighty-eight pounds of mineral pitch,
eighty-eight pounds of pyrogenous oil, and two hundred and six pounds of
small gravel, making a total weight of one thousand and sixty-eight pounds.
This mixture is allowed to simmer over the fire for an hour, being well stirred
until the ingredients are perfectly mixed. The mastic thus prepared is then
ladled out, and poured quickly over the road, it is then spread or scraped with
a spatula, in order that it may only enter the interstices, and not cover the
stones, as the surface of the road would be thereby softened.
SECOND PROCESS. EMPLOYMENT OF ARTIFICIAL CALCAREOUS ASPHALTE
STONE.
put the
As natural calcareous asphalte rock is often not easily procurable, when
this is the case an artificial stone may be substituted for it, which may be
prepared as follows:-Take any soft calcareous stone, chalk, ragstone, sand-
stone, potter's clay, or any other substance of a calcareous or argillaceous
nature, and at the same time solid and absorbent. This material should be
broken to the size above mentioned in reference to the asphaltic rock, and
passed through sieves, after which the stones are dried in an oven. A boiler
is provided capable of being hermetically closed, into which are
following ingredients in any desired quantity, but in the following proportions,
viz., one hundred and ten-pounds of bastenne pitch, or coal tar pitch, of the
same consistence, and five pounds of pyrogenous oil of resin, or any analogous
oil. When these substances have be melted and well mixed, a quantity of
the artificial calcareous asphalte stone, previously dried in an oven, as before
stated, is steeped therein so as to be saturated with the liquid. Supposing the
stones to be from an inch and a half to two inches in size, they must be left
in the liquor about half an hour, or more if necessary.
They are then taken

page_text: out, and put in a vessel constructed in such a manner that the superfluous
bitumen may run off. The time necessary for the saturation of the stones will
depend upon their size or the quantity of bitumen they are required to take up.
By this means any required degree of consistency may be given to the artificial
asphalte rock, according to the temperature of the country where the works
are carried on, in order that the material may always offer the required degree
of resistance. The average quantity of bitumen used is thirteen per cent.
This artificial. asphalto stone is employed in the manner pointed out in the first
process with reference to the employment of the natural asubaltic rock
out, and put in a vessel constructed in such a manner that the superfluous
bitumen may run off. The time necessary for the saturation of the stones will
depend upon their size or the quantity of bitumen they are required to take up.
By this means any required degree of consistency may be given to the artificial
asphalte rock, according to the temperature of the country where the works
are carried on, in order that the material may always offer the required degree
of resistance. The average quantity of bitumen used is thirteen per cent.
This artificial.asphalto stone is employed in the manner pointed out in the first
process with reference to the employment of the natural asphaltic rock
THIRD PROCESS.- EMPLOYMENT OF EITHER NATURAL OR ARTIFICIAL
ASPHALTIC STONE.
Either natural or artificial asphaltic rock or stone may be made up into
mastic to be employed as before with bastenne bitumen, or gas tar, brought
to the same consistency, or any analogous materials, which will impart to it
the character of calcareous asphaltic rock; and, when prepared, this artificial
stone must be broken in pieces and treated in the way above described for
natural stone in the first process already alluded to.
FOURTH PROCESS.-ECONOMY OF THE ASPHALTIC SUBSTANCE.
If it.be required to greatly economize the calcareous asphaltic stone, it would
be advisable to proceed as follows:-Take hard stones broken in the same manner
as for macadamized roads, and of the size of about an inch, as above mentioned,
and prepare them by placing them in baskets, and steeping them in bitumen or
gas tar, in the manner already described in the first process. On being taken
from the bitumen or gas tar, the stones are thrown into some pulverized calcareous
body and well shaken, in order that their surface may be well covered. They
are then spread on the road, as mentioned in the first process, and are used
either as a foundation without anything else, or mixed with broken asphaltic
stone. When the road has been thus covered, the largest interstices are
filled with natural or artificial asphaltic rock of a less size than those already
laid down. They are then beaten down or rolled; as already mentioned in
the first process, and the road is finished with elastic mastic, as explained in
the first process.
Mastic in the form of Sand.-There are certain processes for which the
elastic mastic (already described) should be employed; for instance, for a
wooden bridge or a suspension bridge, where there is constant movement.
For such purposes the mastic should be employed in a hot state, and be of a
viscous and elastic consistence, so as to adhere firmly and not be liable to be

page_text: injured by sudden shocks of bodies running or rolling over it; but for ordinary
'rods the mastic in the form of sand (which is laid down in a cold state) is
preferred, and also for finishing roads as above described. The materials for
and method of preparing this substance are as follows:-Twenty-five pounds
of bastenne bitumen or pitch, or coal tar brought to the same consistency, or
any other analogous substance; sixty-five pounds of pyrogenous oil of resin
or any other analogous oil of a viscous nature, and not liable to be affected
by frost; seven hundred and eighty pounds of calcareous asphaltic rock in
powder, and two hundred and seventy-five pounds of gravel from one twenty-
fifth to two tenths of an inch in diameter. Or if the above materials could not
be readily procured the following may be substituted (videlicit) :-One hundred
pounds of the mineral pitch or other analogous substance; one hundred
pounds of the résinous oil or other analogous substance; six hundred and
ninety pounds of pulverized calcareous earth, and two hundred and seventy-
five pounds of gravel as above mentioned. Instead of common gravel or
sand the bituminous sand of mines may be employed (called in French molasse
bitumineuse), in which case a less proportion of bastenne or other bitumen
may be used. The proportions may, however, be modified according, to the
quality of the materials. When the layer of asphaltic materials has been
sufficiently beaten down the mastic in powder is spread over it with a
'shovel, and a broom is passed over it in order to fill up the interstices between
the stones witliout leaving any on their surface. It is then beaten and rolled,
in order to consolidate the whole firmly together. The roads will now be
found firin enough for any kind of traffic, and will be found to be so unyielding
that no traces of the wheels of vehicles will be left on it. After 'the lapse of
forty-eight hours the roadway made with this pounded mastic will be found
to be as even as that made with the mastic employed in a hot state as above
mentioned.
Brush Mastic. It sometimes happens that the road is worn into holes in
some parts, this may be remedied by laying on several layers of a viscous
mastic composed of two parts by weight of pyrogenous oil of resin, and one
part of bastenne bitumen or 'other analogous material. As each layer is laid
on, pulverized calcareous earth, chalk, or lime is thrown over it, and afterwards
-a small quantity of sand. These substances will become incorporated with
the mástic, and by this means the whole roadway may be covered when there
is not much traffic.
It may be here observed, that the result of the four methods above described
is the same, but the choice of them depends upon the locality, climate, and
the facility of procuring the different materials.

page_text: I would also remark, that the above materials may be made up into blocks
or slabs of any required size, and laid down in the same manner as ordinary
stones. And I would also observe, that the principal feature of this Invention
consists in employing the asphalte in a cold state, and causing it to bind
together by simple compression, the asphalte being rendered,soft by means
the oleaginous or bituminous substances, which after a certain time penetrate
the asphaltic substance, and allow of its binding well together, on being
submitted to beating or rolling or any other suitable pressure. This soft stato
allows also of the introduction of hard matters, such as gravel, stones, rubbish,
and other similar substances. When the surface of the layer of asphaltic matter
has not the required consistence this may be remedied by the addition of a
proportionate quantity of asphaltic rock or pulverized asphalte or any other
calcareous matter, and if too hard by the addition of elastic mastic. The
above materials may also be employed in a cold state for filling up the joints
of stones which are exposed to the action of water or the atmosphere. For
this purpose, after having laid on with a brush a slight coating of oleaginous
or bituminous substances, in order to clean off the dirt and facilitate adhesion
the mastic must be employed in the same manner as when caulking a vessel.
A layer of the elastic mastic above described, or of the brush mastic is then
applied. It may be here observed, that this mode of constructing roads or
ways offers great facilities for the laying down or reparation of gas and water
pipes, sewers, drains, and other similar works.
Having now described this Invention as communicated to me, and the best
means with which I am acquainted for carrying the same into effect, I would
observe in conclusion, that I do not confine myself rigidly to the precise details.
above given, as they may be varied to some extent without deviating from the
principal features of the Invention; but that which I consider to be new, and
therefore claim as the Invention secured to me by the herein-before in part
recited Letters Patent, is,-
First, the preparation of a durable and hard mastic, by the employment of
bitumen or pitch, fixed oils and calcareous substances, as above mentioned.
Secondly, the preparation of an elastic mastic, as above described.
Thirdly, the manufacture of an artificial calcareous asphaltic rock, as
described.
Fourthly, the employment in a cold state of mastic or natural or artificial
asphaltic rock, either alone or in combination with stones or other hard bodies,
for the purpose of forming or covering roads or ways, or for other similar
purposes, as above described.

page_text: Fifthly, the preparation and employment of a mastic, which I call mastic in
the form of sand, as described.
Sixthly and lastly, the preparation of asphalte, in such a manner that it
may be rendered soft without heat, and be caused to bind by simple com-
pression, such as beating or rolling, forming thereby a hard and durable asphaltic
surface.
In witness whereof, I, the said Augustus Roehn, have hereunto set my
hand and seal, this Twenty-eighth day of January, in the year of
our Lord One thousand eight hundred and fifty.
Taken and acknowledged. by Augustus
Rochn (party hereto), at Paris, in
the Republic of France, the Twenty-
eighth day of January, One thou-
sand eight hundred and fifty, before
AUGUSTUS (L.S.) ROEHN.