A Lamp to be Used for Photographing by Magnesium Light.
Year: 1888

page_text: Date of Application, 11th June, 1888
Complete Specification Left, 19th Nov., 1888
Complete Specification Accepted, 21st Dec, 1888
A Lamp to be Used for Photographing by Magnesium Light.
WILLIAM GUTTENBERG 29 Triangle Queens Road Bristol Photographer do hereby
declare the nature of this invention to be as follows
-
A lamp for photographing by magnesium light, consisting of a glass case composed
of two parts namely, the bottom & cover, so fitted that when smoke is generated by
the ignition of magnesium powder inside the lamp, the smoke does not escape until the
lamp is opened. The magnesium powder is mixed with powdered chlorate of potash in
the proportion of one of potash to four parts of magnesium, and for use is laid in a
train on the upper surface of the ground glass bottom and when the cover has been
placed in position the mixture is ignited through a hole cut in one of the ends of the
lamp and a glass door is slid over the hole to prevent smoke escaping The duration
of the exposure is regulated by the length of the train.
For taking portraits the lamp should be suspended a suitable height by means of
chains attached to a strip of wood fitting on the top of the lamp.
My invention consists of a lamp in which magnesium powder is burned in con-
Junction with chlorate of potash, gunpowder, or any other combustible mixture, for
photographing by artificial light It has sides ends and bottom, (and top if so desired,
according to shape) of glass and is composed of two parts, The one part being the
bottom, which is a thick piece of ground glass, whereon a train of the illuminating
mixture is placed for ignition, The other part being the cover for retaining the
smoke generated by the ignition of the powder. The said cover is made of pieces of
clear glass bound together with tin, (the shape of the cover I am describing is that of
an inverted V with ends fitted to the sides)
The piece of glass used for the bottom of the lamp has a wooden frame round it,
with a beading on the upper side of the frame so that when the glass cover is placed
on the frame the upper part of which is covered with felt, the cover just fits outside
the beading making the lamp smoke tight, or, the wooden frame may be attached to
the glass cover and the bottom ground glass can be made to slide into the frame after
the manner of a drawer. In both cases a strip of wood having an angular groove cut
nto it and two chains attached a suitable distance apart in the middle of the strip of

page_text: A
light
issue paper screen should be used Derween the lamp and sitter to sorten
CLAIMS
1st. A lamp for photographing by magnesium light, having all sides made of glass,
thus causing a radiation of light in all directions, so that an even illumination is given
on the subject to be photographed
2nd. A lamp for the above purpose composed of two parts so fitted that the smoke
generated by the combustion does not escape into the room, thus enabling repeated
exposures to be made without getting the image veiled by fog
3rd. A lamp for the above purpose so constructed that it can be suspended in such
a manner that the light falls on the sitter from the same directions as in daylight
portraiture so that no shadow of the sitter is thrown on the background
4th A lamp for the above purpose the construction of which admits of a train of
the illuminating powder to be laid thereby giving a latitude of exposure from one to
any number of seconds according to the length of train, so that the resulting light is
not so sudden and intense thus avoiding the consequent contraction of the facial or
optic muscles caused by a flash light.
5th. A lamp for the purpose stated the size and shape of which are immaterial. It
is advisable not to make it smaller twenty one inches in length, seventeen and a half
inches in breadth and twelve inches in height
The triangular shape is most adaptable.

page_text: I, WILLIAM GUTTENBERG of 29 Triangle, Queens Road, in the city and county of
Bristol, photographic artist 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
The improved lamp in which this invention consists is designed for use in taking
photographs by the light obtained from the combustion of magnesium powder or other
like substance.*
The lamp, which is preferably triangular in section, but which may be of other
shape, is composed of glass on all sides, the glass being suitably let into a proper frame
of wood or metal or of both. The base is separable from the upper part which may be
conveniently termed the cover.
At one end of the cover is a sliding door governing an aperture through which
ignition of the illuminant is effected. The magnesium powder or other suitable
illuminant is luid in a train on the upper surface of the base, which train commences
near the sliding door aforesaid. The proportions of the train vary with the required
intensity of the light.
Around the frame of the base extends a tongue which fits into a corresponding
groove provided in the frame of the cover. The cover is secured to the base by chains
or bands which embrace the two and are connected to a beam laid along the top of the
cover. To this beam is attached a loop or link whereby the lamp is capable of
suspension.
Referring to the accompanying sheet of illustrative drawings, Fig. 1 thereon
represents a side elevation of a lamp constructed in accordance with this invention
Fig. 2 is an elevation of that end at which the door is situated, and Fig. 3 18 a
transverse section.
The base is composed of a glass plate a supported at the sides and ends in the
frame b of wood, metal or other suitable material. Extending round the frame 6 of
the base is a tongue 6' which fits into a corresponding groove provided for its reception
in the frame c of the cover and keeps the lamp smoke-tight. The latter is composed of
glass plates d, d' bound together at the corners by the strips e of metal or other suitable
material
1
At one end of the cover is a glass door f free to slide vertically in the supports fl
and fitted with a knob få as a bearing place for a finger or fingers in raising the door.
The train of magnesium and chlorate of potash, or of other combustible illuminant
suitable for the purpose, is laid along the base plate a, terminating at one end near the
door f covering au aperture in the end of the cover In the lamp illustrated this
aperture is indicated by a dotted semicircle The cover is surmounted by the beam
loosely laid along the top and grooved or recessed at the underside to receive the apex
of the cover.
At one side of the beam are attached chains h which, after having been
passed below the base, are carried up and secured at the other side of the beam To
g

page_text: h
the upper part of the beam is attached a loop by which the lamp is capable of being
suspended. Being of glass on all sides, the light yielded when the lamp is used
suspended is shed in the same way as daylight and, consequently, the occurrence of
shadows belund the person or object being photographed is obviated
The smoke given off by the combustion of the magnesium powder is retained in the
lamp and hence the studio or photographing chamber is kept free therefrom and the
delay hitherto necessary for dispersion of such smoke before another photograph can
be taken is avoided, the lamp being first conveyed from the apartment for the
purpose of allowing the smoke to escape by removing the cover
The base and cover being separate, the structure is free to yield at the joint
between the frames b and c, within the limit permitted by the chain h, under the
influence of the pressure of the gas generated by the ignition of the illuminant
Having now particularly described and ascertained the nature of this in-
vention, and in what manner the same is to be performed, I declare that what I
claim 1s
1 Consti ucting a lamp for use in photographing by magnesium or other like light,
with sides, ends and bottom or base of glass set in a suitable frame or frames, substan-
tially as herembefore set forth
2 Constructing a lamp for use in photographing by magnesium or other like light,
with a base or bottom such as a of glass, on which or on a plate or strip of glass
superposed on the said base the powder or mixture for illumination is received,
the said base or bottom being set in a suitable frame such as b, and with glass
sides d¹ set in a suitable frame such as c, and furnished with a door such as f
governing access to the interior, substantially as herein before described and shown
in the accompanying sheet of illustrative drawings.
3 The combination with a lamp for photographing by magnesium or other like
light, such as is claimed in the foregoing claims, of a grooved beam or bar such
as g surmounting the lamp, and chains such as h (or equivalent wires, bands or
cords) whereby the cover and base are bound together and the lamp made capable
of suspension for distribution of the light as required for avoidance of creation of
shadows, as herein before described.
in the
4 The frame with tongue b¹ fitting into a corresponding groove
frame c, whereby the lamp is rendered smoke-tight and play is allowed between
the cover and the base under the influence of the pressure of gas generated by
combustion of the illuminant, substantially as described
Dated this 17th day of November 1888.
NICHOLAS WATTS,
Applicant's Agent