An Improved Signalling Device and Cooking Stove, intended for Military Purposes.
Year: 1895

page_text: Date of Application, 29th Jan., 1895-Accepted, 29th Feb.,
1896
COMPLETE SPECIFICATION.
An Improved Signalling Device and Cooking Stove, intended for
Military Purposes.
I FREDERICK AUGUSTUS LASCELLES DAVIDSON North Camp, Aldershot, in
the County of Hampshire, Captain, Royal Scots Fusiliers, do hereby declare the
nature of this invention and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
This invention relates to means and apparatus for transmitting signals made by
flashes of light, which apparatus is also available for use as a cooking stove,
searchlight, and for other similar purposes.
In carrying out my invention I propose to construct a rectangular apparatus.
of any suitable material in the interior of which I provide a lamp and also a
reflector.
A lens may be used and on the exterior side of the apparatus immediately beyond
the lamp-chamber I insert a noiseless and detachable metal shutter by means of
which I am enabled to project a beam of light or to cover and uncover the light
rays in such a manner as to convey a desired message.
The signalling device may also be used as a helio- or lunastat in which case
I insert one or two suitable mirrors in sockets provided on the top of the apparatus.
The aforesaid metal shutter is removed from its former position and placed
immediately in front of the first mirror and its legs in suitable sockets formed to
receive them. A sight vane is also provided for use with the apparatus when
used as a helio- or lunastat by means of which a hole in the centre of the first
mirror and the object aimed at are aligned.
For long distance signalling a light telescope is provided which is retained in
position in the manner hereafter described.
When it is desired to use the apparatus as a cooking or heating stove, the
lamp chimney, which is telescopic in construction and may be double to keep
off the outside atmosphere thus preserving the draught, is pulled up to the
extent required according to the oil or lamp used and a.regulation mess-tin or
other holder placed upon a ledge formed just beneath a lid above the cowl or
hood with which the chimney is provided and which lid is hinged and thrown
back for this purpose. The warming or cooking may then be done by the heat
arising from the lighted lamp or gas beneath. Or I may utilise the sun's rays
for this purpose in which case I provide a suitable burning glass fitted into a
hollow aluminium or other upright provided with an arm and slow motion screws
by means of which I am enabled to deflect the sun's rays on to the lower part
of the holder containing the substance or liquid to be heated or cooked.
The whole apparatus may he supported when in use by a tripod or placed
upon a wall or other similar position as may be convenient.
Referring to the accompanying drawings for a fulier explanation:
Fig. 1 shews the apparatus in use as a signalling lamp.
Fig. 2 shews the apparatus when used as a helio- or lunastat.
Fig. 3 represents the apparatus in use as a cooking stove with lamp or sun.
Fig. 4 shews the apparatus with tripod packed for transport.
Upon these drawings, A represents the apparatus furnished on top with a
convenient handle a and fitted at the rear with hinged doors B B¹ B2. One of
the upper doors B¹ or B2 or a space between these doors is provided with a
pocket 6 to receive a signallers watch. The interior of the apparatus is divided

page_text: by partitions into compartments preferably three in number, the centre one
being of wire gauze or perforated metal to conduct away heat, and the outer
casings may be lagged interiorly with asbestos or similar material to keep them
cool. This chamber contains the oil or similar lamp or other source of
illumination C. Lamp C is provided with a large parabolic or other reflector
and wick-raisers at its rear, and this reflector may, if desired, be furnished with
a sight hole either above or on one side of its centre, to enable the operator
to obtain a view of the lamp or wicks whilst burning. The wick holders
themselves are slightly arched and on the circumference of a large curve, the
wick being trimmed and cut to this shape. A thin piece of simple or coloured
glass either whole or in strips, or a thin sheet of mounted mica fits into a
suitable ledge in front of the chamber and just behind the shutter and can be
taken out when the shutter is removed.
A small sliding door b¹ is likewise provided in the door B to enable the
operator to raise or lower the lamp wicks and regulate the draught without
opening door B. The chamber is provided with a telescopic chimney c¹ which
is a part of it and this chamber with its chimney form the inner casing of the
apparatus, being thus well protected from weather. The chimney c¹ is furnished
with a cowl or hood c² to keep out wind and rain.
The compartments on either side of the central chamber are divided into shelves
for holding accessories such as wicks, oil reservoirs, matches, wick-trimmers,
goggles, gimlet, file, plain and coloured glass and mica slides, cipher tablet, cleaning
rags, oil funnel, fog-horn for use in foggy weather when other means of
communication are not possible, and varions other articles required by a military
signaller and such as will be hereafter mentioned.
Beyond the lamp C I may sometimes use a paralleling lens preferably formed
in two parts, screwed together and the whole lens may be screwed in and out of its
socket to alter the focus. The lens would be so situate that the flame would be at
its principal focus. Immediately in front of the chamber or the lens is a noiseless
detachable shutter E, somewhat resembling a Venetian blind, which may be worked
by the thumb and forefinger of either hand, and provided with a thumb-piece and
spiral spring. This shutter E is retained in position before the lamp chamber
and in some cases the lens, by means of metal clips e and has a pair of metal
legs e¹.
When it is desired to signal by artificial light the lamp or other source of
illumination is lit and the desired message conveyed by opening and closing the
shutter E for periods of varying duration according to the code in use.
When using the apparatus as a heliostat or lunastat I preferably unclip and
remove the chimney d. The shutter E is taken from its position in front of
the lamp chamber or the lens by unfastening the clips e. Its legs are then
inserted in suitable sockets 2 in the top of the apparatus. A mirror F provided
with a vertical slow motion screw is then placed in position behind the shutter E
by means of which the rays of the sun or moon may be thrown in any desired
direction. A second mirror F¹ is required only when the sun or the moon is directly
behind the operator. Between mirror F and shutter E, I place a sight-vane G
fitting into a socket provided therefor in the top of the apparatus A, and I am
thereby enabled to align the mirror and object. The message is then conveyed
as in the former instance by opening and closing shutter E for varying durations
of time.
The telescope T, screwed into its position, is for use when signalling is being
carried on at a great distance and when not being employed may be pushed in,
there being a clip to keep it safe; or it may be unscrewed out of position and
used apart from the apparatus. It may be drawn out through a hole or
groove H in the rear of the apparatus and this hole or groove may be covered
by a sliding piece of metal instead of the clip. A luminous compass t is also
fixed in the top of the apparatus A for use in conjunction with a map.
To utilize the apparatus as a cooking or heating stove I proceed in the

page_text: following manner. I remove the mirrors and sight vane G and stow them away in
suitable pockets situated in the outer casing. The shutter E is also restored to
its original position, viz. :-in front of the chamber or lens, to which when not in
use it acts as a guard. The chimney is unclipped and drawn out to such a
length as to suit the kind of lamp or burner used and to regulate the draught.
The hinged lid above the cowl c² at the top of the chimney is then thrown
back and a regulation mess-tin or other holder m placed in position upon a
ledge provided for this purpose. Lamp C may then be lighted and the tin and
its contents warmed or cooked. If it is wished to economise oil as is sometimes
the case and when there is a hot sun I utilize a powerful burning glass n fitted
to the end of an upright k provided with an arm and slow motion screws, (not
shewn on the drawing) whereby I am enabled to follow the path of the sun and to
deflect its rays on to the lower part of the mess-tin or other holder m which is at
the focus of the lens, and boil or heat its contents.
The legs ppl of the tripod on which the apparatus may be supported when in
use, may be attached to the bottom of the apparatus A by any suitable devices
such as by means of spikes, screws or socket-joints, and their outer ends are
spiked to enable them to obtain a firm hold in the ground and to prevent them
slipping. One of the legs p¹ may be fitted with an extension arranged to be
worked by a rack and pinion whereby the lamp may be elevated or depressed.
A small chained wedge is also carried in the interior of the apparatus A by
means of which the apparatus may be slightly tilted to an inclination backward
or forward, when it is being used without the tripod.
The legs p p are moreover hollowed out and a number of cylindrical metal oil
tubes with screwed caps are inserted therein and kept in position by any suitable
means, thereby economising space and dispensing with oilcans I may also utilize any
remaining space in the outer compartments for storing oil in metal reservoirs fitted
with small taps, screwed heads or similar outlets and I may arrange to insert small
cupboards lockers or drawers in various parts of the apparatus to contain wicks
for the mineral oil or other lamp, chemicals for gases, limes for use with the
oxyhydrogen light or incandescent lamps when these latter sources of illumination
are available. do not however restrict myself to any particular illuminant but
may use whichever I consider most suitable for the special purpose such as, in
addition to those mentioned above coal gas, acetylene gas, the incandescent gas
lamp or burner, or electricity, for each of which I have a special burner or
lamp as the case may be, to fit the same chamber exactly and to take the place
of the oil lamp.
Instead of hollowing out the legs of the tripod and inserting metal reservoirs,
I may make these legs ppl of metal tubes and utilize these as the oil reservoirs,
providing them with a suitable outlet or outlets.
The whole or any part of the above apparatus may be made of any material
which I think most suitable for its intended use, and the whole apparatus A may
be perforated to allow a free draught of air to reach the lamp and to keep the
apparatus and its contents cool. The shelves and drawers in the partitions may be
also grooved or perforated or made of such material for the same purpose.
The apparatus A may be carried by the handle a or as a knapsack by means of
braces passing through eyes s upon one side thereof as shewn on Figures.1 and 2,
and the tripod carried in the hand by means of a strap handle in which signalling
flags may also be strapped up. Or a hook in one of the legs may be caused to
support the apparatus by means of the handle a and the whole carried on the
shoulders.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. The combination of a signalling device and cooking stove as and for the
purposes described.

page_text: 2. In a portable signalling and cooking device arranged to be operated by means
of an oil lamp, the particular construction of the lamp chamber and outer casing
for controlling and regulating the supply of air, as described and illustrated.
3. A portable signalling and cooking device capable of being operated by means
of a lamp or other source of heat and light, constructed combined and arranged
-as described and illustrated upon the accompanying sheet of drawings.
Dated this Twenty-eighth day of January 1895.