IMPROVEMENTS IN BLAST LAMPS
Year: 1875

page_text: LETTERS PATENT to Robert Lavender, of Kirkcaldy, in the County
of Fife, North Britain, Oil Merchant, for the Invention of
"IMPROVEMENTS IN BLAST LAMPS."
Scaled the 1st February 1876, and dated the 2nd November 1875.
PROVISIONAL SPECIFICATION left by the said Robert Lavender at the
Office of the Commissioners of Patents, with his Petition, on the
2nd November 1875.
I, ROBERT LAVENDER, of Kirkcaldy, in the County of Fife, North
Britain, Oil Merchant, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN BLAST LAMPS," to be as follows:-
This Invention has reference to a new or improved mode and means
of producing the draught or "blast" of air in or for lamps, and which
enables them to burn better with the heavier class of hydrocarbon and
other oils than bas been found practicable heretofore. And the nature
and novelty of this said Invention consist in drawing in the air through an

page_text: annular or other shaped space at the bottom of the lamp. This draught
is produced in a new manner as applied to lamps, namely, by suction,
caused by the lateral action of a small jet of steam (or it might be of
air or other gaseous fluid) through a nozzle at the neck or throat of the
escaping funnel above the light.
In other respects the lamps may be made of any ordinary con-
struction, the essential feature of novelty being the causing of the
draught and assisting combustion by exhausting the waste or burnt gases
through the funnel or chimney by the lateral action of a blast or jet of
steam, air, or other vapour or gaseous fluid.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Lavender in the Great Seal Patent Office
on the 2nd May 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
LAVENDER, of Kirkcaldy, in the County of Fyfe, North Britain, Oil
Merchant, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Second day of November, in the year
of our Lord One thousand eight hundred and seventy-five, in the thirty-
ninth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Robert Lavender, Her special licence,
that I, the said Robert Lavender, my executors, administrators, and
assigns, or such others as I, the said Robert Lavender, 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 BLAST LAMPS," upon the condition (amongst others) that I, the
said Robert Lavender, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said

page_text: 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 Robert Lavender, do hereby declare
the nature of my said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the
following statement in writing, reference being had to the accom-
panying Sheet of Drawings, and to the letters and figures marked
thereon, that is to say:-
My said Invention has reference to a new or improved mode and
means of producing the draught or "blast" of air in or for lamps, and
which enables them to burn better with the heavier class of hydrocarbon
and other oils than has been found practicable heretofore. And the
nature and novelty of this said Invention consist in drawing in the air
through an annular or other shaped space at the bottom of the lamp.
This draught is produced in a new manner as applied to lamps, namely,
by suction, caused by the lateral action of a small jet of steam (or it
might be of air or other gaseous fluid) through a nozzle at the neck or
throat of the escaping funnel above the light.
In other respects the lamps may be made of any ordinary con-
struction; the essential feature of novelty being the causing of the
draught and assisting combustion by exhausting the waste or burnt
gases through the exit funnel by the lateral action of a blast or jet of
steam, air, or other vapour or gaseous fluid. The jet of steam or other
pressure clastic fluid is brought from any suitable contiguous pressure
generating vessel through ordinary tubes or pipes, so as to draw and
force or eject the burnt or waste gases out of the lamp through the
funnel, which produces a partial vacuum within the lamp, and causes
the air entering from below to rush in towards the flame to assist
combustion and lengthen the flame.
The force of the blast jet is regulated by a reducing valve or hand
tap or valve fitted on the steam or blast pipe near the lamp, and to
assist the lateral action of the blast jet, the exit funnel of the lamp may
be made slightly trumpet-shaped towards the outer end.
And in order that the nature, novelty, and mode of performing my

page_text: said Invention may be fully understood, I will now proceed to describe
several Figures on the Sheet of Drawings, which I have hereunto
appended for the purpose of showing the best modes and means I am at
present aware of for putting the Invention into effect or practice, the
same reference letters indicating the same or like parts in all the Figures
where shown.
Figures 1 and 2 are a sectional elevation and a horizontal section on
the irregular line 11, in Figure 1, of a blast lamp constructed in
accordance with and illustrative of one modification of my said Inven-
tion or improvements.
The lamp represented in these Figures is of the large one-flamed class
suitable for lighting up the works around mine shafts, yards, sheds, and
large workshops, ironworks, foundries, and other public works, and also
railway stations, harbours, and other places where strong light is
required.
Referring to the construction of lamps shown in these Figures; A is
the frame of the lamp or lantern made square with glass B' in the four
sides, preferably inserted in narrow strips to lessen the liability of
breakage of the glass by sudden heating and cooling, and with a sheet
metal bottom at A', but it might be of glass, having the parrafin or oil
lamp proper C secured thereto by four snugs c, and projecting some
little distance up through a hole in its centre, leaving an annular space c¹
for the admission of air to the burning wick, the flame from which
projects in a long cylindrical column or candle flame shape up the
centre of the lamp, as indicated in dotted lines at z, towards the roof or
crown A" which is preferably bevelled on all sides in the form of a
pyramid towards the centre A", where it is fitted or formed with a long
cylindrical or slightly trumpet-shaped exit funnel A*. The lamp C is
made in a somewhat usual form with an outer and inner shell C, C¹,
respectively, leaving the annular space or vessel at C" for the reception
of the oil, and for the annular wick C² which is raised and lowered by
two or more pronged wires or wick carriers d attached to a movable cross
head D, and through which the revolving screw spindle D' works,
actuated by the handle D" below so as to raise and lower the cross
head D and wick C* as desired, within the centre cylindrical air space C',
which is preferably open below but closed above by the plate d' through

page_text: which the forks d work, and having a small hole in the centre c" to
supply air to the inside of the burning part of the wick and flame.
The oil is preferred to be kept in the shallow rectangular vessel E at
one side of the lamp, large enough to contain oil to supply the lamp for
the night or watch during which it is to be used, and connected at its
lower side by the large duct or pipe E¹ to the oil and wick chamber C",
so that when the vessel E is filled with oil by the filling mouth E", its
upper surface will be nearly on a level with the top c' of the lamp C,
and a little above the bottom A' of the lantern or case A, so that no oil
would escape at this part and the pipe E' would draw off all the oil from
the vessel E before the light would die out. The steam pipo from the
boiler is shown at F controlled by a hand tap F, fitted on it near the
top of the lamp, where it enters and is coiled or turned so as to project
up with its extreme open end in the centre of the throat at A of the
discharge funnel A* where it is fitted with a suitable nozzle F" so as to
project a jet of steam as indicated at fout through the ſunnel, which by
its lateral action draws out the waste hot gases from the top part A" of
the lantern or caso of the lamp A and so ventilates it, producing a
partial vacuum or diminution of the pressure within, which has the
effect of drawing in the fresh air to supply combustion through the
annular space c to the flame (as indicated by the arrows in Figure 1)
within the cap or chimney e, shown particularly in detached elevation
and plan in Figure 3, and which under these improvements is preferred
to be formed of thin iron or other metal contracted conically or in a
dome shape to a central orifice close over and much smaller than that of
the burning wick, so as to heat the gases and contract the flame into
the smaller central orifice e', from which it springs in the long
cylindrical or candle flame form already described, assisted by the
suction towards the discharge funnel A³, a small jet of air being also
drawn in through the central disc and hole d', d", as before mentioned,
which thus gives a strong and brilliant light radiating equally in all
directions.
When steam is used in the pipe F for producing the lateral discharge
action of the smoke, a small pipe G is led therefrom (controlled by a
tap G¹) down or into and through the oil supply vessel E in an un-
dulating manner at G", or it might be round the sides of the vessel with
its open end passed finally out through the vessel G" (where the

page_text: exhaust steam or water would be drawn off at the open end of the pipe,
or by a syphon or tap, as indicated at G in Figure 4), so as to heat the
oil and prevent it from freezing in cold weather, and insure its constant
flow through the tube E' to the lamp O; or otherwise, as shown in the
detached sectional view of the lamp C, Figure 4, the tube E' might |
be made large and cylindrical with a close steam jacket G' round it, into
which the steam pipe G would be led, so as to heat and maintain the oil
in a liquid state in passing through the pipe E' to the lamp without the
necessity of the undulating pipe G", the condensed steam passing off
at the syphon pipe G or there might be a tap for that purpose.
Although steam has been described as used in this case high pressed
air or other gases may be used and brought in by the pipe F from a
generator, so as to produce the jet f and discharge of the gases through
the funnel A, all as described in reference to steam.
And although these improvements have only been described for 1
common lamps and lighting purposes, it is to be understood that they
may be used with advantage for special purposes, such as for ships'
lights, lamps, or lanterns, railway carriage and engine lamps, fog signal
lamps, and lamps for large buildings or halls where gas was not
obtainable.
Having thus particularly described the nature and mode of performing
my said Invention, I wish it to be understood that I do not confine
myself to precise details or general construction of the lautern A or
lamp C, as many variations may be made therefrom without departing
from the essential feature of my said Invention; neither on the other a
hand do I desire to claim the particular form or construction of several
parts of the lamp shown and described, except in combination with my
improvements, but what I consider novel and orignal, and therefore
claim as the Invention secured to me by the herein-before in part recited
Letters Patent is,-
First. The general construction and combination of the parts of blast
lamps and their fittings or connections, substantially as herein described
in reference to and shown in the accompanying Drawings or any merc
modification thereof.
Second. The ventilation and discharging of the waste or burned gases
from the interior of blast lamps by the use of a iet of steam nin

page_text: other gascous fluid in and through the funnel above the flame, sub-
stantially as herein described.
In witness whereof, I, the said Robert Lavender, have hereunto
set my hand and seal, this Twenty-first day of April, in the
year of our Lord One thousand eight hundred and seventy-
six.
Witness,
JOHN BROWN,
Patent Office,
96, Buchanan Street,
Glasgow.
ROBERT LAVENDER. (L.S.)