Just in front, and between the sitter and {200} the reflector, upon a proper stand, were used those paper muslin screen before described; also screens of tissue paper. These screens, however, when they were used, required so much time for a sitting, that some other medium, as a protection to the eyes, became absolutely necessary. The most plausible thing that suggested itself was blue glass; but, as this could not be found, numerous were the expedients proposed by the friends of the art, who from time to time visited our rooms. At the suggestion of Professor Mapes (who is ever ready to assist those in perplexity), a trough of plate glass s, about twenty-eight inches square in the clear, and from three to four inches thick, was filled with a solution of ammonia sulphate of copper, and mounted on the frame as in the sketch, which, for a time, answered extremely well; soon, however, decomposition of this solution became apparent from the increased length of time required for a sitting, although to the eye of an observer, no visible cause for such long sittings could be pointed out. Professor Mapes being appealed to, suggested that to the above solution a little acid be added which acted like a charm—shortening the time for a sitting from six, eight, or ten minutes to that of about one. Decomposition, however, would go on by the action of light and heat through the solution. New solutions were tried, when the whole were finally abandoned as being, too uncertain and troublesome. (The reflecting apparatus R, was placed upon the stand as in the sketch, with a wedge for elevating the camera, between it and the table, to obtain the image properly upon the plate.) A quantity of blue window glass was next obtained, and holes drilled through the corners of it, and several sheets were wired together to increase the size, and, when complete, was suspended from the ceiling in its proper place, and so arranged that when a person was sitting, this sheet of glass could be moved to and from, the object of which was to prevent shadows on the face of the sitter produced from the uneven surface of the glass. This latter contrivance was used until a perfect plate of glass was procured.
The number of persons desirous of obtaining, their miniatures, induced many to entertain the idea of establishing themselves in the Art as a profession, and numerous were the applications for information; many persons paying for their portraits solely with the view of seeing the manner of our manipulations, in order that they might obtain information to carry on likeness-taking as a business.
The reflecting camera being a very troublesome instrument to make, and difficulties besetting us from every source, but little attention could be given to teaching others; and, indeed, as the facts seemed to be at this time, we knew but little of the necessary manipulations ourselves. In course of time, several established themselves. The first one, after ourselves, who worked the discovery of Daguerre for portrait taking in this city, was a Mr. Prosch; followed soon after by many others, in almost all cases copying the reflecting arrangement for light, as figured above, many using it even after we had long abandoned that arrangement for a better one.
Innumerable obstacles to the rapid advance of the daguerreotype, presented themselves almost hourly, much to the annoyance of ourselves, and those dependent upon our movements for their advancement. Among the most difficult problems of the day, was the procuring of good plates. Messrs. Corduran & Co. were among the first to supply the trade; at that early day, however, it was a very rare thing, to be able to procure an even perfect surface, from the fact that a pure surface of silver could scarcely be obtained, the manufacturers deeming it too much trouble to prepare silver plated copper with pure silver—the result was, that in attempting to polish perfectly such plated metal as could be procured, the plates would become cloudy, or colored in spots, from the fact of having more or less alloy, according as more or less of the silver surface was removed in polishing the plate fit for an impression. To explain more clearly, it was the practice of most silver platers to use an alloy for silver-plating. In the reduction of the ingot to sheet metal, annealing has to be resorted to, and acid pickles to remove oxides, etc. The number of times the plated metal is exposed to heat and acid in its reduction to the required thickness, produces a surface of pure silver. The most of this surface is, however, so rough as to be with difficulty polished, without in places removing entirely this pellicle of pure metal, and exposing a polished surface of the alloy used in plating. Whenever such metal was used, very unsightly stains or spots frequently disfigured the portraits. The portrait, or portion of it, developed upon the pure silver, being much lighter or whiter than that developed upon the alloy; it therefore appeared that the purer the silver, the more sensitive the plate became. Accordingly, we directed Messrs. Scovills, of Connecticut, to prepare a roll of silver-plated metal, with pure silver; it fortunately proved to be a good article, but, unfortunately, a pound of this metal (early in 1840) cost the round sum of $9. Like descriptions of metal, the same gentlemen would be glad to furnish, at this time, for $4. Soon after this, some samples of English plated metal, of a very superior quality, came to our possession, and relieved us from the toil of making and plating one plate at a time, an expedient we were compelled to resort to, to command material to meet the pressing demands for portraits.
Having it now in our power to obtain good plated metal, a more rapid mode of polishing than that recommended by Daguerre was attempted as follows:
This metal was cut to the desired size, and having a pair of “hand rolls” at hand, each plate, with its silvered side placed next to the highly polished surface of a steel die, was passed and repassed through the rolls many times, by which process a very smooth, perfect surface was obtained. The plates were then annealed, and a number of plates thus prepared were fastened to the bottom of a box a few inches deep a foot wide, and eighteen inches long; this box was placed upon a table and attached to a rod connected to the face plate of a lathe, a few inches from its centre, so as to give the box a reciprocating motion. A quantity of emery was now strewn over the plates, and the lathe set in motion. The action produced wag a friction or rubbing of the emery over the surface of the plates.
When continued for some time, a greyish polish was the result. Linseed, when used in the same manner, gave us better hope of success, and the next step resorted to was to build a wheel and suspend it after the manner of a grindstone. The plates being secured to the inner side of the wheel or case, and as this case revolved, the seeds would constantly keep to the lower level, and their sliding over the surface of the plates would polish or burnish their surfaces. This, with the former, was soon abandoned; rounded shots of silver placed in the same wheel were found not to perform the polishing so well as linseed. Buff-wheels of leather with rotten-stone and oil, proved to be far superior to all other contrivances; and, subsequently, at the suggestion of Professor Draper, velvet was used in lieu of buff leather, and soon superseded all other substances, both for lathe and hand-buffs, and I would add, for the benefit of new beginners that those who are familiar with its use, prefer cotton velvet. The only requisite necessary is, that the buffs made of cotton velvet should be kept dry and warm.
The greater number of operators, with whose practice I am familiar, use, for polishing plates, prepared tripoli, imported from France, or Browne’s rotten-stone. The former of these articles is very objectionable, inasmuch as there is no positive certainty of being enabled to procure or make the article of uniform grit—the nature of the substance rendering, it impossible to reduce it to varying degrees of evenness, by the well known process of washing, for that purpose, and the burning of rotten-stone changes its chemical nature somewhat, at the same time rendering, this invaluable article harsh and gritty. And especially, no reliance can be placed upon burned rotten stone if purchased from those who do not give very great attention and care to its preparation; and the same remarks apply to rouge.
The best article for polishing Daguerreotype plates is rotten-stone, such as can be procured in any town, prepared after the following manner: Procure, say half a dozen wide-mouthed bottles, of suitable dimensions, numbering each from one to six. Put into No. 1 about half a pound of rotten-stone, and nearly fill the bottle with water. Then, with a proper stick or spatule, mix well the rotten-stone and water; after which, let No. 1 rest for, say one minute, then carefully pour off into bottle No. 2 (or, what would be better, draw off by a syphon) as much of the floating particles of rotten-stone as is suspended in the water. Again fill bottle No. 1 with water, agitate it as before, and decant it to bottle No. 2, care being taken to draw off only the suspended particles of rotten-stone.
When a sufficient quantity of washings from bottle No. 1 is collected into bottle No. 2, a similar process must be gone through, as above stated, for No. 1; the difference being in the care required, and in the time allowed between the stirring or mixing the rotten-stone and water. The floating particles of rotten-stone, after four minutes’ subsiding, will be found fine enough for the finest Daguerreotype polishing required.