American Hand Book of the Daguerreotype [50]
Suppose we make a critical examination of one of the repudiated plates. From its external appearance we have little hesitation in pronouncing it to be French; indeed, this presumption is strongly corroborated by the fact that it is ornamented upon one of its corners with a brand to designate the manufactory from which it emanated.
Upon close inspection we cannot fail to notice a striking peculiarity upon the surface; the roughness is very remarkable; the planishing hammer has left amazingly visible indications of its busy work. One would suppose the manufacturer intended the surface of the plate to represent the undulations of the sea, instead of that smooth and level character so strongly recommended by M. Daguerre.
Such a plate necessarily requires at the hand of the operator considerable labor before the surface is in a proper condition to receive a suitable polish from the buffer. The least reflection in the world should teach any one that so long as the undulatory character continues upon the surface of the plate, it is in a very imperfect condition for buffing, because the buffer cannot touch every point equally; the elevated portions alone receiving a high degree of polish while the depressed portion, from their roughness acting as nuclei, gather dust, rouge, and other foreign bodies, so detrimental to sensitiveness. The secret of the superior judgment and skill of one operator over another, is intimately connected with this point: his success depends very much upon the first process of cleaning the plate.
Let us examine the manipulation of the complaining operator. He takes one of these plates and gives it a careful scouring with rotten-stone and alcohol or any other liquid preferred for this part of the operation--that is, he gives it what he terms a careful scouring-- very gently indeed because, from the frequent trials he is in the habit of making in the camera, he fears he will rub the silver entirely away before he succeeds in obtaining a good impression. The dark patches, specks, and granular appearance resulting entirely from the unevenness of the surface of the plate, look like copper to him, and he is surprised that he should have rubbed away the silver so soon, particularly by such delicate handling.
The judgment and experience of the successful operator, however, teach him that scouring injures a plate less than buffing. He knows that unless the hammer marks be obliterated, he cannot by the buffer produce a surface of uniform polish and sensitiveness, without which a fair proof is extremely doubtful; he knows that the time employed in the preliminary operation of cleaning the plate properly is economy.
There is a style of French plates in the market, denominated heavy, which are truly excellent, if properly managed. Much patience, however, is required to remove the marks of the hammer; but with tripoli and alcohol the surface is readily cut down, and the plate is then susceptible of a beautiful black lustre by polishing with the buffer. The complaining operator could not succeed by his own method with one of the plates; he would encounter all manner of clouds and other unaccountable phenomena; he would imagine this plate entirely worn out before it was half cleaned, and soon fix in his own estimation the reputation of the heavy plate.
In making a choice of plates, therefore, it would appear to be a matter of perfect indifference with an experienced operator what kind he would use, except so far only as the labor required in cleaning them was to be taken into consideration.
The distinction between a scale plate, a Scovill No. 1, S. F., heavy A, star, crescent, eagle, or any other brand, consists in the superior finish of some, and the thinness of the silver in the cheaper qualities.
Consequently, let the complaining operator but employ the diligence inculcated in this article, to clean his plate thoroughly, so as to bring it to a perfectly even and level surface, and he will seldom be troubled with specks, clouds, dark patches, and the host of other obstacles which heretofore