IMPROVEMENTS IN MINERS' SAFETY LAMPS
Year: 1879

page_text: LETTERS PATENT to Andrew Howat, of Manchester, in the County of Lancaster,
for the Invention of "IMPROVEMENTS IN MINERS' SAFETY LAMPS."
Sealed the 22nd August 1879, and dated the 25th February 1879.
PROVISIONAL SPECIFICATION left by the said Andrew Howat at the Office
of the Commissioners of Patents on the 25th February 1879.
ANDREW HOWAT, of Manchester, in the County of Lancaster.
IN MINERS' SAFETY LAMPS."
"IMPROVEMENTS
My Invention consists in admitting the air to support combustion through tubes
or apertures in the lower part of the lamp or oil chamber, of such diameter and
length as to prevent the flame passing out of the lamp. The upper portion of
lamps of the usual construction is made of wire gauze through which the gas in
some cases is driven, thus causing explosions. Now I make the upper portion of
the lamps of a number of tubes or flues through which no flame can be forced, con-
sequently when my improved lamp is used there is no danger of explosion.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Andrew Howat in the Great Seal Patent Office on the 23rd
August 1879.
"
ANDREW HOWAT, of Manchester, in the County of Lancaster. IMPROVEMENTS
IN MINERS' SAFETY LAMPS."
My Invention consists, Firstly. In admitting the air to support combustion
through tubes or flues in the lower part of the lamp or oil chamber, of such diameter
and length as to prevent the flame passing out of the lamp, which tubes are covered
at their inner ends by a cap lined with wire gauze. Secondly. In making the
upper portion of the lamp of a number of tubes or flues covered at the upper end
with wire gauze through which the products of combustion pass and which
effectually prevent any flame from passing out of the lamp.
And in order that my Invention may be fully understood, I will describe the
accompanying Sheet of Drawings. Fig. 1 is an elevation of my improved lamp,
and Fig. 2 is a section of the same; Fig. 3 is a plan of the oil chamber, shewing the
air admission tubes and the gauze cap covering their inner ends; and Fig. 4 is a
plan in section, shewing the tubes for carrying off the products of combustion.
a is the oil chamber, b is the frame, and c the glass; a, a, are the tubes or
flues for admitting air to the flame; d is a cap or chamber lined with wire gauze,
covering the inner ends of the air admission tubes; e, e, are vertical tubes for
carrying off the products of combustion; f is a cap made partly of wire gauzo,
covering the ends of the vertical tubes; g, g, are projections on the cap which como
in contact with the plate at the top of the lamp when it has been unscrewed a
certain distance and prevent the cap from being removed.
Having thus described the nature of my Invention, and the manner of per-
forming the same, I wish it to be understood that I do not limit myself to any
particular size, shape, or arrangement of tubes or flues, but what I claim is, first,
admitting air to the flame of miners' lamps by tubes or flues, the outer ends of
which are placed at the side of the oil chamber or lower part of the lamp; and
secondly, carrying off the products of combustion through vertical flues or tubes,
substantially as shewn and described.
In witness whereof, I, the said Andrew Howat, have hereunto set my hand
and seal, this Twenty second day of August, One thousand eight hundred
and seventy nine.