DAGUERREOTYPE.

67

E.— Simplification of the Daguerreotype Processes.

The extreme expense of the apparatus and plates, as supplied by thepatentee, induced me, in the very first stage of my experiments, toendeavour to construct for myself, a set which should be equally aseffective, and les3 expensive.

I was soon satisfied that all the arrangements might be much simpli-fied, and any one may have constructed for himself, for less than twentyshillings, a set of apparatus, by which he shall be enabled to producepictures equalling, in every respect, those procured with the set sold attwenty pounds.

My apparatus consists of a deal box the size of my plates, and threeinches deep, with a thin loose board in the bottom. This board is wellsaturated with the tincture of iodine,—the spirit is allowed partially toevaporate, and then, being put in its place, the plate is adjusted at aproper height above it, varying the height according to the temperature,—the box being closed, the operation is completed in about threeminutes. Another deal box, having a glass in one side, and a bottomof sheet iron, which is slightly concaved to contain mercury, withgrooves upon which the plate may rest at the proper angles, serves tomercurialize the plates. My camera, which I use for every photographicprocess, is described in a future chapter. It is sometimes convenient,particularly when travelling, to use a piece of amalgamated copper,which may be prepared, when wanted, by rubbing it with some nitrate ofmercury. The expense of the plates may be very much reduced: in-stead of using copper plated with silver, I would recommend the use ofsilvered copper, which every one can prepare for himself, at a verysmall expense. The following is the best method of proceeding:—

Procure a well planished copper plate of the required size, and wellpolish it, first with pumice stone and water, then with snake stone, andbring it up to a mirror surface, with eithe^ rotten-stone, or jeweller’srouge. Plates can bo purchased in a higrT state of preparation fromthe engravers. Having prepared the copper plate, well rub it with saltand water, and then with the silvering powder. No kind answers betterthan that used by clock-makers, to silver their dial plates. It is com-posed of one part of well washed chloride of silver, five parts of creamof tartar, and four parts of table salt. This powder must be kept ina dark vessel, and in a dry place. For a plate six inches by five, asmuch of this composition as can be taken up on a shilling is sufficient.It is to be laid in the centre of the copper, and tho fingers beingwetted, to be quickly rubbed over every part of the plate, addingoccasionally a little damp salt. The copper being covered with thesilvering, it is to bo speedily well washed in water, in which a littlesoda is dissolved, and as soon as the surface is of a fine silvery white-ness, it is to be dried with a very clean warm cloth. In this state theplates may be kept for use. The first process is to expose the plate to