IMPROVEMENTS IN APPARATUS FOR VENTILATING BUILDINGS
Year: 1857

page_text: LETTERS PATENT to John Leslic, of Conduit Street, St George's, Hanover
Square, in the County of Middlesex, for the Invention of "IMPROVEMENTS
IN APPARATUS FOR VENTILATING BUILDINGS."
Sealed the 29th October 1857, and dated the 4th May 1857.
PROVISIONAL SPECIFICATION left by the, said John Leslie at the Office
of the Commissioners of Patents, with his Petition, on the 4th May
1857.
I, JOHN LESLIE, of Conduit Street, St George's, Hanover Square, in the
County of Middlesex, do hereby declare the nature of the Invention for
"IMPROVEMENTS IN APPARATUS POR VENTILATING BUILDINGS," to be as follows:-
This Invention has for its object improvements in apparatus for ventilating
buildings. For these purposes an air shaft is fixed to the ceiling or upper
part of a building in such manner as to rise through the roof and on the
exterior of the air shaft is formed an enclosed chamber, open at bottom and
closed at top, by which combination of parts the heated atmosphere of the
building will enter the enclosed chamber around the air shaft and keep it

page_text: warm, and will thus induce a rising current through the air shaft. The
entrance into the air shaft and surrounding chamber may be made ornamental
when desired.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Leslie in the Great Seal Patent Office on the
2nd November 1857.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
LESLIE, of Conduit Street, St George's, Hanover Square, in the County of
Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourth day of May, in the year of our Lord One
thousand eight hundred and fifty-seven, in the twentieth year of Her reign,
did, for Herself, Her heirs and successors, givo and grant unto mc, the
said John Leslie, Her special licence that I, the said John Leslie, my
executors, administrators, and assigns, or such others as I. the said John
Leslie, 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
term 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 APPARATUS FOR
VENTILATING BUILDINGS," upon the condition (amongst others) that I, the said
John Leslie, my executors or administrators, by an instrument in writing
under my, or their, or one of their hands and seals, should particularly describo
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 Leslie, do hereby declare the
nature of the said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement thereof, that is to say:—
This Invention has for its object improvements in apparatus for ventilating
buildings. For these purposes an air shaft is fixed to the ceiling or upper
part of a building in such manner as to rise through the roof, and on the
exterior of the air shaft is formed an enclosed chamber, open. at bottom and
closed at, top, by which combination of parts the heated atmosphere of the

page_text: building will enter the enclosed chamber around the air shaft and keep it
warm, and will thus induce a rising current through the air shaft. The
entrance into the air shaft and surrounding chamber may be made ornamental
when desired.
Having thus stated the nature of my Invention, I will proceed more fully
to describe the manner of performing the same.
When the Invention is to be applied to ventilate a room of a building
where there is a fire-place and chimney, it is preferred to use, an air fluc,
which, rising from the ceiling of the room to the outer atmosphere, is in contact
with the chimney on one side, in order that it may derivo heat therefrom.
The lower end of this air flue is open to the room, so that the air in the room
may pass into and through it, and out at the upper end of the flue into the
open air. In addition to and in combination with such air flue one or more
air flues is or are used, surrounding or partly surrounding the one above
mentioned, the lower ends of which air flues are open to the room, in order
that the heated air therein may pass into and fill them, but not pass out there-
from, by reason of the upper ends of such surrounding or partly surrounding
flues being closed. By this arrangement the air fluc first mentioned will not
only derive heat from the chimney, but also from the heated air constantly
within the air flues in contact therewith, which are closed at their upper
ends.
When it is desired to apply my Invention to rooms where there is no
chimney or at a distance from the chimney (if there be one to the room),
particularly where there are no rooms above the one to be ventilated, in
such cases I prefer the air flue which is open at the upper end to be within a
single flue, or be surrounded by flues which rise as high or nearly as high as
the air flue, but such surrounding flue or flues are to be closed at top, by which
the open air flue will be heated by the heated air constantly in the surrounding
flue or flues, and which cannot pass away by reason of the upper end or ends
of those flues being closed, by which means the draft through the air flue first
mentioned will be insured. It is preferred to make both the open air flue and
also the closed air flue, when in contact with the chimney, of earthenware,
but when not in contact with a chimney I prefer to use iron, though other
materials may be used. In order to prevent rain falling down the open air
flue an inverted hollow cap or cover may be used, leaving ample space for the
escape of the air into the open atmosphere. It will be evident that the pas-
sages into the open air flue and the closed air flues at their lower ends may
be made ornamental, and the upper ends may also be made ornamental.

page_text: What I claim is, the combination of open and closed air flues herein
described.
In witness whereof, I, the said John Leslie, have hereunto set my
hand and scal, this Second day of November, in the year of our
Lord One thousand eight hundred and fifty-seven.
Witness,
GEO. PITT.
JOHN LESLIE. (L.S.)