A NEW AND USEFUL COMPOSITION TO BE APPLIED AS A COVERING TO THE SIDES AND ROOFS OF BUILDINGS, AND FOR VARIOUS OTHER PURPOSES
Year: 1857

page_text: LETTERS PATENT to Nathan Appleton Dyar, of the State of Massa-
chusetts, of the United States of America, for the Invention of "A NEW
AND USEFUL COMPOSITION TO BE APPLIED AS A COVERING TO THE SIDES AND
ROOFS OF BUILDINGS, AND FOR VARIOUS OTHER PURPOSES."
Sealed the 5th May 1857, and dated the 9th March 1857.
COMPLETE SPECIFICATION filed by the said Nathan Appleton Dyar at
the Office of the Commissioners of Patents, with his Petition and
Declaration, on the 9th March 1857, pursuant to the 9th section of
the Patent Law Amendment Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, be it
known, that I, NATHAN APPLETON DYAR, of the State of Massachusetts, of
the United States of America, have invented "A NEW AND USEFUL COMPOSITION
TO BE APPLIED AS A COVERING TO THE SIDES AND ROOFS OF BUILDINGS, AND FOR
VARIOUS OTHER PURPOSES," and I do hereby declare the nature of my said
Invention, and in what manner the same is to be performed, are particularly
described and ascertained in and by the following Specification (that is to
say)-
My Invention consists in the employment of sulphuric acid, wherewith to'
treat compositions containing hydrocarbons, the result being the production
of a material or composition having body, elasticity, and other properties

page_text: fitting it for various purposes, in manner as will be herein-after fully
described.
It is well known that of late years various roofing compositions have come
into use, most of which are composed principally of tar and rosin, to which
are sometimes added chalk, sand, and clay. These mixtures are, I believe,
generally melted together, and applied in a fluid state to such roofs as are
inclined so slightly from a horizontal plane that the composition shall not
"run" when the application is first made; sheets of paper, felt, or other
fibrous material being first attached to the roof to be covered, to prevent the
composition from flowing through the open spaces in between the boards of
said roof; they are too fluid to be applied without the intervening sheathing,
they are too easily affected by the heat of the sun, and cannot readily be
applied to surfaces having an inclination of more than ten degrees from the
horizon.
For several years I have been engaged in endeavoring to produce a
composition which 'might overcome these obstacles, and be capable of applica-
tion not only to any inclined surface, but to the upright sides of a building,
without the intervention of the fibrous material. In my many experiments
I have produced and tried a great number of mixtures, until I have, as I
think, found one which will fully answer, the requirements.
I
.
My method of preparing it is substantially as follows:-To a barrel of gas
tar, or about thirty-two. gallons, I add about one hundred and eighty pounds
of yellow ochre and about one gallon of whale oil. I thoroughly incorporate
these, and then add to 'and mix with them fifty or more pounds of sulphuric.
acid, according to the consistency I wish the mixture to possess..
The peculiar action of the sulphuric acid on the mixture of coal tar with
the oil and earthy base is to produce in its union with the hydrocarbon of the
coal tar an elastic body, and the quantity of the acid used must not be large
enough to leave an acid reaction in the mass; the oil combines with the
whole, and acts as a solvent of the greasy part of the tar.
I have found that phosphoric acid and arsenic acid may be substituted
for the sulphuric acid with somewhat similar effect, but generally I prefer the
latter..
The mixture. when thus prepared is ready for immediate application to any
horizontal, inclined, or upright surface for which it is intended, the proportion
of sulphuric acid used in the composition being varied according to the
inclination of the surface to which it is to be applied.
For upright or very steep surfaces, the quantity of acid has to be much
greater than for horizontal or but slightly inclined ones. I generally apply it

page_text: by means of a trowell, much in the same manner in which common mortar or
plaster is applied.
After its application it gradually becomes very tough and hard, though
retaining its elasticity to such extent as to give and yield to the shrinkage or
opening of the boards to which it may be applied without any rupturing.
When I wish the composition to speedily become very hard, I add to and
mix with it a small quantity of oil of turpentine, which has the desired effect.
Sand is to be sifted over the composition after its application to make a foot-
hold, and it then makes an excellent protection from fire, as it is very hard
to inflame when it has been exposed for a short time.
I would remark, that though the proportions I have named above are
about the ones I have generally used, they may be perhaps varied without
detriment.
I would also remark, that other earths than yellow ochre may be used, as
may some other fish oils, some other acids, and some other tars than those
above mentioned, but I have as yet found nothing that fully answers in place
of the particular oil, tar, or acid mentioned.
This composition has been applied by me to an exposed surface for two
years, and does not crack, melt, break, or let air or water through it, and
seems, with the exception of having become very hard, to retain all its
properties as at its first application. It may be applied to advantage as a
cement for cellar bottoms, or walls, or to stop crevices in exposed situations,
and there are many other purposes to which it may be applied, to which I will
not now further allude.
I claim the employment of sulphuric acid, or an acid having a similar
effect, in the treatment of substances or compositions containing hydrocarbons,
in the manner and for the purposes essentially as above described.
In testimony whereof, I have hereunto set my signature and seal, this
19th day of February, 1857.
NATHAN APPLETON DYAR. (L.S.)