=The Inking Tables=, two in number, are provided one at either end of the machine, necessitating two sets of inking rollers—one of leather for applying the thick ink, and another of composition for supplying the “half-tone,” the latter set requiring such light application to the plate that no riders are required. There are also the usual distributing rollers, to which the ink is generally supplied by the printer as may be necessary, the quantity being so small that no actually satisfactory automatic duct has yet been devised. A proper adjustment of the consistency of the two inks to the requirements of the plate in hand is a matter of considerable delicacy, for should the ink supplied to the leather rollers be too thin it is immediately removed from the printing plate by the composition rollers; these again transfer it to the table devoted to the thin ink, and a general “wash up” is the necessary result. The ink first supplied to the leather rollers should be as stiff as possible, afterwards reducing as experience may dictate, while to the composition or tone rollers merely coloured varnish, or even varnish alone, is applied, as the latter often remove enough colour from the printing plate to sufficiently tint the varnish applied to their surface. The leather rollers should be cleaned daily by scraping, and the composition set washed, unless the weather be very cold or damp. In such cases they may be allowed to stand under ink, as they will in that condition be less susceptible to atmospheric changes. =Double Printing= is sometimes resorted to for work of a high class, and when negatives too thin to produce good results otherwise are unavoidably used, such work is usually printed on chalk paper and without masking. The printing plate is usually inked up twice and an impression taken; without removing the impression from the cylinder the plate is again twice inked and a second impression pulled on the same piece of paper, the two images being exactly super-imposed. The great gain in contrast will be understood when it is considered that while the high lights of the picture gain absolutely nothing, the strength of the shadows is exactly doubled. The results produced in this way are simply astonishing when contrasted with silver prints from the same negatives. ADVERTISEMENTS. HUGO KOCH, LEIPZIG-CONNEWITZ, GERMANY, MANUFACTURER OF COLLOTYPE STEAM PRESSES. Awarded First Prizes at all Exhibitions where our Presses have competed. —> World’s Exhibition, Antwerp, 1885, Diploma of Honour. <— [Illustration] THE KOCH COLLOTYPE STEAM PRESS IS THE BEST IN THE MARKET MADE IN FOUR SIZES. AUTOMATIC FEED BOARD, FRISKET, AND INK DUCT. If desired, the press can be arranged also for litho or type printing