its 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
ge