Note E — Chapter IV

Since the foregoing pages have been in type an entirely new feature in the line of apparatus has been introduced; this is W. & W. H. Lewis's Patent Plate-holder with solid glass corners. These Holders have every requisite for excluding the light from the sensitive surface; they are accompanied with a "shut off," so that when the slide is drawn no light can reach the glass. This, in connection with the unequalled advantage of the solid corners, makes them the most desirable article for the Operator. Humphrey's Journal, in referring to these Holders, says:—

"We are always glad to note every step which our mechanics make towards improvement on the apparatus used by our practical photographic operators, and make the present announcement of one which has only to be known to be readily understood, and to be seen to be appreciated. A patent has recently been granted for making solid glass corners, which are to be attached to plate-holders, and form the most perfect article that has ever been introduced. Heretofore the operator has had the corners of his plate-holders made with separate pieces of glass, cut so as to fit the corners of his frames; these are only glued or grooved in, and are constantly coming apart, falling out, and annoying in many ways; for our part, we never have considered them as fit for use in any manner. We look upon the present improvement as destined to entirely supersede all the methods heretofore introduced. In this case the collodionized or albumenized plate can come in contact with no other substance than a single piece of glass, and consequently there is far less liability of accident from either the staining of the plate or breaking of the holder. The rapid favor this improvement has gained already shows its great advantage over all other methods heretofore employed."