By A.J. JARMAN.
For some time past it has been the desire of many photographers to
have at hand a ready means of producing a powerful and highly actinic
artificial light, suitable for the production of negatives, and easily
controllable. Several forms of apparatus have been designed, and I
believe have been, to a certain extent, employed successfully in
portraiture. But it has been well known for many years that the
electric light was just the light that would answer the photographer's
requirements, owing to its possessing great actinic power; but the
cost of its production was too great for general adoption; indeed,
such might be said of it now as far as dynamo-electric machines and
steam or gas motors are concerned, for the majority of photographers.
It is true that several influential photographers have already adopted
the use of the electric light for portraiture, but the primary cost of
the apparatus employed by these firms is far beyond the reach of most
portraitists. The apparatus about to be described is one that has been
carefully worked out to meet the wants of the photographer in almost
every particular; in fact, with this apparatus, portraits can, and
have been, produced in an ordinary sitting room, as good and as
perfect as if taken in a well-lighted studio.
[Illustration: FIG. 1.]
The generator of the electric current consists of a series of voltaic
elements of zinc and carbon--forty-eight in number--these elements
being made up of ninety-six zinc plates and forty-eight carbon plates;
thus the generator consists of forty-eight voltaic elements arranged
in rows of twelve; they are all carefully screwed upon suitable bars
of wood, and these bars are joined by other cross bars, which bind the
whole in a compact form; the battery being suitably connected so as to
produce a current of very high electro-motive force, and so arranged
over their exciting trough that the plates can be raised or lowered at
will, as seen in Fig. 1, which will explain itself almost at first
sight.
The troughs are made of mahogany, put together with brass screws, and
well saturated with an insulating compound which also makes them acid
proof; the cells are charged with a saturated solution of bichromate
of potash, to which has been added twenty fluid ounces of sulphuric
acid to each gallon.
[Illustration: FIG. 2.]
To produce the electric current, all that is needed is to lower these
suspended elements down into the trough, having previously connected
the wires as shown in Fig. 1, to the electric lamp, Fig 2. At once a
light starts up, between the carbon pencils, of a thousand-candle
power or more. With a light of this power, a large head on cabinet or
carte size plate may be produced in three or four seconds.
The generator occupies a floor space of three feet six inches by two
feet, and stands two feet six inches high. The cells will cost 5s. to
charge, and will produce upward of sixty negatives before being
exhausted. All that is necessary, in recharging, is to lift the
elements up out of the way, take out the troughs by their handles and
empty them, charging them again by means of a toilet jug. When
replaced, the whole apparatus is fit for use again; the whole of the
above operation occupies but a quarter of an hour, and as there are no
earthenware cells employed, there is no fear of breakage.
The small amount of labor and cost of working the above apparatus will
compare favorably with the production of the electric light from a
dynamo-electric machine for the photographer, and when we consider
that the cost of the whole of the above apparatus, consisting of a
generator automatic lamp, reflector, and all the necessary
appendages, is less then one-tenth of the dynamo machine, motor,
shafting, etc., to produce the same result, it would seem to have a
greater claim for its adoption with those who wish to employ the
electric light, whether for work at night, use in the sitting room, or
to assist daylight on the dark and foggy days of winter.
Fig. 2 shows the arrangement of the electric lamp. A is the automatic
regulator; B, the reflector; C, top extension of the reflector; D,
small tissue paper screen to prevent the intense arc-rays from coming
in contact with the sitter; E, stand with sliding rod. This appendage
can be wheeled about with ease, as it is arranged to run upon four
casters.
When the generator is in use it may be placed within easy reach of the
operator, so that the exposure may be made by lowering the elements in
their troughs just for the requisite time, and withdrawing immediately
the exposure is made; there is no need to fear any inconvenience from
deleterious fumes as none are given off, so it may be used in any
studio or sitting-room without any inconvenience from this source, and
as far as many trials have gone, it seems to meet every requirement
demanded by the photographer for the production of portraits by means
of the electric light.--_Photo. News._
* * * * *