IMPROVEMENTS IN THE MATERIALS EMPLOYED IN CONSTRUCTING AND WORKING ATMOSPHERIC RAILWAYS
Year: 1845

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN ROBERT
JOHNSON, of Alfred Place, Blackfriars, in the County of Surrey, Chemist,
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 Sixth day of December, in the ninth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
John Robert Johnson, my exors, admors, and assigns, Her éspecial license, full
power, sole privilege and authority, that I, the said John Robert Johnson, my
exors, adiñors, and assigns, or such others as I, the said John Robert Johnson,
my exors, admors, 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.
expressed, should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, my Invention of
"IMPROVEMENTS IN THE MATERIALS EMPLOYED IN CONSTRUCTING AND WORKING
ATMOSPHERIC RAILWAYS;" in which said Letters Patent is contained a proviso
that I, the said John Robert Johnson, shall cause a particular description of
the nature of my said Invention, and in what manner the same is to be
performed, to be inrolled in Her said Majesty's High Court of. Chancery
within six calendar months next and immediately after the date of the said.
in part recited Letters Patent, as in and by the same, reference being there-
unto had, will more fully and at large appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the said
John Robert Johnson, do hereby declare that the nature of my said Invention,
and the manner in which the same is to be performed, are fully described and
ascertained in and by the following statement thereof, reference being bad to
the Drawing hereunto' annexed, and to the. figures 'and letters marked thereon,
that is to say:
My Invention consists,-first, in a new composition for sealing the valve and
closing the joints of the traction tubes of certain descriptions of atmospheric rail-
ways. The compositions hitherto used for this purpose do not retain their proper
consistence under varying temperatures, and from containing beeswax in large
proportions, are expensive. I obviate these inconveniences by adding to various
mixtures of oily, resinous, and bituminous substances, of too soft consistence to
be used alone, such a quantity of clay, chalk, or ochre, dry and in fine powder,
as will bring the oily mixture to the proper..consistence, which consistence,
from the infusibility of the earthy matter, is not or is but slightly affected by
change of temperature. I find that every description of wax, oil, resin, and
pitch may be mixed with each other in such proportions as to serve for this
purpose when incorporated with the earthy matter; and I find that all the
substances. which are neutral, that is to say, which do not act chemically upon
the oily or resinous mixture which are infusible within the range of atmospheric
temperatures, and which are insoluble in water, may be used for giving
consistence to that mixture. I however prefer china clay or whiting
in fine powder, as being more economical than others. I find the following
mixture to answer well, but I do not confine myself to the mixtures herein
mentioned, nor to the proportions given, videlicet:-Palm oil, one part; brown
resin, two parts; china clay in fine powder, four parts. I can also effect
the above object by mixing in various proportions the insoluble soaps pre-
pared by combining fats with an oxide or earth with oily or resinous sub
stances; but the material so formed is less economical and not more effective
than that produced as above described.
I claim the use of argillaceous, calcareous, or other insoluble and infusible.
matters in combination with oleaginous, resinous, and bituminous substances,
for the purpose of preparing a composition for sealing the valve and joints of
tubes of atmospheric railways requiring such materials.
And I also claim the use of the insoluble soaps when mixed with oily or
resinous substances for the sealing of the longitudinal valves of atmospheric
railways.
My Invention consists, secondly, in a new material for lining or lubricating
the interior of the traction tubes of atmospheric railways. The substance

page_text: hitherto used for this purpose is stearine or stearic acid, but insoluble soap
prepared by combining fats and metallic oxides has been proposed. I find
that à more economical material is produced by incorporating with mixtures
of solid fat, or oil ånd resin, or pitch, sufficient of the earthy matters before
described to give consistence to the said mixtures. The following mixture
answers well for this purpose, but I do not confine myself thereto,-resin,
seven parts; stearine, four parts; tallow, four parts; clay, twelve parts.
"
I claim the use of argillaceous, calcareous, or other insoluble and infusible
matters in combination with fatty, resinous, or bituminous substances, for the
purpose of producing a material fit for lining or lubricating the interior of the
traction tubes of atmospheric railways.
.
in use.
My Invention consists, thirdly, in an economical substitute for the leather
now used for the longitudinal valve of atmospheric railways. The material I
use for this purpose is a fabric woven or felted in the form of a belt or strap
of the proper. breadth and thickness to form the valve, or cut in strips of the
proper breadth from woven or felted web. The fabric when woven may be
of cotton, hemp, flax, or wool, but I prefer the former. I render this fabric
impervious to air and moisture, and in other respects fit for its purpose, by
impregnating its fibres with and cementing them' together by a varnish, of
such a nature that when dried it shall be unacted upon by oil or fats, and
possess sufficient elasticity to bear the bend or flexure to which it is subjected
I find that the drying or siccative oils, such as linseed or nut oil, to
possess this property. That which I prefer is linseed oil, rendered more
siccative by being boiled, and known under the name of boiled oil; and in
causing it to penetrate the fibres of the fabric I operate in the following
manner: I heat the oil until the temperature rises to 250° of Fahrenheit or
thereabouts. I immerse the strap in the oil and retain it there until the air
and vapour have been expelled from its interstices. I then raise it and pass
it, while hot through between a pair of iron rollers sufficiently close to expel
the greater portion of the oil, leaving sufficient only to coat the threads with
a thin film. I then place it to oxidize or' dry gradually in a warm room.
When the oil is oxidized or dryed, I pass it again through oil (which however
is not now to be heated above 200°) through between the rollers and again
expose the fabric in the warm room. These operations are repeated until the
interstices of the fabric become filled with the successive coats of the varnish,
and the fibres are cemented together into one mass. When this is the case
the surface of the varnished strap may have its inequalities removed by friction
with pumice stone, and a last coat of the varnish given by a brush.
I claim as my Invention the treatment of fabrics by means of elastic

page_text: varnish, of such a nature that when oxidized or dried it is unacted by fatty
bodies, and in such a manner that the interior and exterior fibres, are cemented
with the said varnish, and by which the fibres are rendered impermeable to air
and moisture, and thereby fitted for use as a substitute for leather for the
longitudinal valve of atmospheric railways.
:
My Invention consists,, fourthly, in new materials for and new modes of
constructing the traction and connecting pipes of atmospheric railways. The
materials which I employ for this purpose are calcareous cements, such as
Roman cement, .Keene's cement, and the like, which possess such properties
as allow them to be cast into form, and do not require burning. The cement is
mixed or "guaged" with sand or fine gravel and water rammed into moulds
of proper form for the pipes, as in forming 'columns and other articles, which
is well understood. But I prefer operating in the following manner:
Let Figure 1 represent a side and end view of the tube to be cast. I form
iron moulds for this tube in the manner .represented by. Figures 2, 3, 4, 5, in
which A, B, C, are the external parts of the mould held together by the
flanches a, a, a. D', D, are the cores or mandrils to form the hollow centre.
E', E, are the ends fixed by the flanch b, b, to A, B, C, through which the
mandril D¹ passes, and by which it is retained in its proper position. .I uso
this mould. in the following manner:-Having coated the interior with a thin
coat of stiff tallow I bolt together the parts A, B, C, and one of the ends. E';
the core D' is then inserted through the end and held in its place at the other
extremity of the tube by means of wooden wedges or other contrivances, and
the core. De is inserted in its place. The whole being placed vertically with
the end E' downwards, I fill the interstice between the cores and sides of the
mould with well-washed gravel, from which the superfluous water- has, been
just drained. The gravel must be screened so that the larger pieces are not
more than one inch or thereabouts, and the smaller not less than a quarter of
an inch. When the cement, like that of Keene's, is some hours in solidifying
or "setting" I proceed in the following manner:-I fix a pipe to the lower, end
of the mould, as at Figure 6, and I connect. the upper part of this pipe with a
vessel G, provided with an agitator for mixing the cement with water. . When
properly mixed I, open, the cock F, Figure 6, and allow the fluid cement to
descend the pipe and rise through the gravel, forcing the air before it. When it
has risen to the upper part of the mould I shut off the cock, disconnect the pipe
from the vessel, then fix the end D2, and invert the mould, so as to be able to
remove the cock F, and prevent the cement setting within. it. When tho
cement has "set" the core is forced through the ends E, E, without their
being removed from the external parts of the mould, and when separated the

page_text: tube is allowed to harden for some time longer, and is then removed by forcing
open the flanches. When cement, like Roman cement, sets rapidly I operate
in a different manner. The mould is filled as before with wet gravel; the
end D is then fixed in its place, and the joints of all the parts of the mould
are closed with a composition similar to that used for closing the valve of the
atmospheric railway, and which is described above.. A pipe (H), in commu-
nication with an air pump, is attached as at Figure 2, and another pipe, with
cock and branches, is in communication with a vessel and agitator G.. "The
cock I is closed, and the cock H.being opened a vacuum is formed within the
tube. When the guage in connection with the air-pump shews that this is
attained, the cock (II) is closed, and that at (I) opened, when the cement
mixed within the vessel (G)' flows down into the gravel, and. occupies: the
spaces from which the air has just been removed. The pipe, cock J, and
vessel G are immediately separated and cleaned to prevent their being closed
by the cement. As soon as the cement has solidified the core is removed, and
the tube allowed to dry, and extracted as before. For removing the core
considerable pressure is sometimes necessary, and for this purpose a hydraulic
press with an orifice in the head for the admission of the core will be found
most convenient. . When. the pipes produced. by these processes are dry and
somewhat seasoned, I proceed to render them impervious to air and moisture
by causing them to absorb coal tar which has had its more volatile portions
separated by distillation. The melted tar. may be laid on with a brush so long
as it is absorbed by the porous surface; but when the pipes or tubes are made
of Roman cement I prefer to immerse them and to allow them to become
soaked by the melted tar; when raised, the superfluous tar is removed, and
the pipe placed for several days in a hot chamber, where the tar becomes still
further indurated by evaporation, and the cement, having its interstices filled
with the bitumen, becomes of the nature of asphalt as to impermeability and
resistance to atmospheric influence. Care must be taken that the pitch or
distilled tar be not heated too high, and thus separate the water which is an
essential constituent of these cements. If Keene's cement be employed the
temperature must not rise beyond the heat of boiling water, but when Roman
or other calcareous cements of similar nature are employed the temperature
may exceed this point with advantage, but should not be allowed to exceed 250°
Fahrenheit. Although I have only shewn one description of tube in the
Drawings, the new materials and new modes of construction are applicable to all
forms of traction and connecting tubes used for atmospheric railway purposes.
I also wish it to be understood, that although I have in the foregoing descrip-
tions described the tubes as formed entirely of Roman and other calcareous

page_text: :cements, yet I do not confine myself exclusively thereto. I find that parts of
the said tubes may be formed with advantage of cast or wrought iron, as
at Figure 7, and in. joining the said metal parts to the said tubes I prefer to
operate in the following manner: I lay on the surfaces of the said metal
parts to be brought in contact with the parts formed of cement a coating of
-pitch or other. adhesive substance; I then place the metal parts in the moulds
in their proper position,. and I proceed to cast the cement into tubes as before.
The hollow surfaces of the metal parts are thereby perfectly closed by the
cement; and the film or layer of adhesive substance causes adherence, while it
allows of motion when the different expansion or contraction of the different
substances renders such motion necessary..
I claim in respect to this part of my Invention the forming of traction and
connecting-tubes, of atmospheric railways by. moulding or casting them of
cements which do not require after-burning, and rendering the materials imper-
vious to air, as herein described.
In witness
I, the said John Robert Johnson, have hereunto set my
hand and seal, this Sixth day of June, in the year of our Lord Ono
thousand eight hundred and forty-six.