American Hand Book of the Daguerreotype [55]
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
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