IMPROVED MEANS FOR PREVENTING THE SPREAD OF FIRE FROM ONE PART OF A BUILDING TO THE OTHER
Year: 1883

page_text: PROVISIONAL SPECIFICATION left by Alexander Melville Clark at the Office
of the Commissioners of Patents on the 18th September 1883. Commu-
nicated to him from abroad by William Hickman Dolman, of St Helens in
the County of Columbia and State of Oregon, United States of America,
Miner
ALEXANDER MELVILLE CLARK of the firm of A. M. and W. Clark of 53 Chancery
Lane in the County of Middlesex, Fellow of the Institute of Patent Agents
"IMPROVED MEANS FOR PREVENTING THE SPREAD OF FIRE FROM ONE PART OF A
BUILDING TO THE OTHER" [communicated to him from abroad by William Hickman
Dolman, of St Helens in the County of Columbia and State of Oregon, United
States of America, Miner]
The object of this Invention is to prevent the spread of fire either by ascending
above or descending below the room or storey, in which it originated.
This object is attained by the application of sheet iron and ashes to the joists,
rafters, and other timbers of the structure as hereafter described.
The joists having been set in place in the walls of the building, I fasten to the
under edge sheet-iron of say from No. 24 to No. 30 American gauge, the sheets
extending beneath all the joists, and the intervening spaces, and forming a ceiling
of sheet iron. I then deposit on the sheet iron, and between the joists two to four
inches in depth of fine sifted dry ashes or earth banking the ashes or earth well up
against the sides of the joists. Strips of wood are secured to the underside of the
sheet iron beneath the joists by nailing through the sheet iron to the joists. To
these strips the lathing is secured to receive the plastering there being a small space
between the lathing and the sheet iron to permit the plaster to key.
Fillets are nailed to the sides of the joists, one and a half inches to three inches
below the upper edge or top of the joists, and upon which sheets of iron are
uailed.
I then commence laying the floor and as the laying progresses I entirely fill the
spaces between the floor and the sheet iron with ashes or earth taking care that
there is no hollow space under the floor, in which the air can circulate; and that
no chips of wood or any other combustible material are mixed with the ashes or
earth.

page_text: A dead air space between the ashes or earth on the ceiling, and the sheet iron
beneath the floor, is left to prevent dampness, except at the ends where they enter
the wall, at which point, the entire space should be filled up with ashes or earth to
prevent the joists taking fire through the heating of the walls by a fire in an
adjacent building.
In the event of fire breaking out in the room or story of which the floor is
constructed as above described the ashes or earth will smother and dampen the
underside of the flooring boards and prevent their rapid and total burning and in
no case is it possible for a fire on the floor to reach and burn more than a small
part of the upper edge of joists while the ashes or earth remain in place.
Should a fire break out in the room or story of which the ceiling is constructed
as above described, the lath and plastering and the wood strips would probably
be destroyed, but the joists would remain intact being protected by the sheet iron
ceiling and the ashes or earth banked up against them.
To prevent the woodwork from burning at any opening in the floor or roof and
to stop the draft or fire being carried up or down I nail sheet iron to the side of
the woodwork, leaving a space of two or three inches between the two, which I fill
with ashes or earth. It is very important that the woodwork at all the openings
should be thus protected. The trap door for the opening hollow and is made of
sheet iron of a thickness of two to four inches, and filled with ashes or earth.
Timbers for use as joists rafters or posts in the construction of a building are
protected and rendered fire proof by nailing to it narrow cross strips of wood about
-one-foot apart, and of the required thickness, according to the intended thickness
of the protective covering. To these strips I nail sheet iron, and fill the space
between the timber and the sheet iron, with ashes or earth.