IMPROVEMENTS IN LIGHTING AND. VENTILATING
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Coleman Defries at the Office of
the Commissioners of Patents, with his Petition, on the 29th September
1864.
I, COLEMAN DEFRIES, of the Firm of Jonas Defries and Sons, of Hounds-
5 ditch, in the City of London, Manufacturer, do hereby declare the nature
of the said Invention for "IMPROVEMENTS IN LIGHTING AND. VENTILATING;"
to be as follows:-
My improvements refer principally to the lighting by gas of public
buildings, theatres, music halls, or other large spaces where much light is
required, and also that provision should at the same time be made for the
ventilation of the area between floor and ceiling.
For the better comprehension of my Invention I will in this my Provisional
Specification confine myself to the description, say, of a music hall with level
or plane ceiling and ordinary bent card roof. I divide, in this instance, the
ceiling into squares by means of joists (say, of iron), and between each joist I
leave an 'open space, varying in width according to the area of the ceiling.
These joists crossing at right angles form large and small square and oblong
openings. Between ceiling and roof I arrange my lighting apparatus, which is
composed of a series of sun lights or other gas burners placed under covers or
shades, which are constructed in the shape of an inverted funnel; the inner part
of each of these metal shades is galvanized or otherwise treated to assist in
throwing down the light and forming reflector.
The pipes of these shades are
led into other and converging pipes, and finally into a horizontal cylinder or

page_text: -
eylinders, which traverse under the entire roof, and have exits into the open air.
These cylinders are furnished with cowls or other contrivances for securing the
exit of the products of combustion and exclusion of the atmospheric air. To
return to the ceiling, which is yet in its skeleton state of unfilled openings, I
fill the larger spaces with squares of glass, the oblong apertures with move-
able prisms of glass placed crossways in relation to the length of the aperture,
and the square openings formed by the meeting and crossing of the joists
with cut-glass lustres made in openwork, so, as to allow the air to pass freely
through them.
the whole ceiling appears
but the parts filled by the
By the foregoing it will be perceived that while
from below to be a solid or unbroken plane, all
larger squares of glass (or panes of glass) is open, that is to say, the prisms
placed crossways in the openings between the joists are not placed quite close
together, and (as do the openwork lustres) allow the air to pass freely. Thus
when the gas is lighted a strong light is thrown downwards through the glass
ceiling, and the prisms and lustres appear like brilliant ornaments, but serve
nevertheless for. the escape of the foul and heated air which. rises from the
audience (or area between floor and ceiling) into the area between ceiling
and roof, where it is caught up and passed through the escape cylinders
before mentioned into the open air.
I would here observe that although I have confined the foregoing descrip-
tion to a plane ceiling in squares, in order the more clearly to explain the
nature of my Invention, it is however equally applicable to ceilings in com
partments, or stages, and the openings for ventilation by means of prismis and
Justres may be of any form or size, and if prisms and lustres be in some cases
considered as too expensive the openings may be filled with perforated glass,
slips of glass, or any transparant material, so that provision be made for
ventilating.