If letters, quadrates, or furniture rise up and black the paper, they should be put down, and the quarter locked up tighter. If any letters are battered, the quarter they are in must be unlocked, and perfect ones put in by the compositor. When bearers become too thin by long working, they should be replaced by thicker ones. When the form gets out of register,—which will often happen by the starting of the quoins which secure the chase,—it must be immediately put in again, as there can scarcely be a greater defect in a book than the want of uniformity in this particular. If picks, produced by bits of paper, composition, or film of ink and grease or filth, get into the form, they must be removed with the point of a pin or needle; but if the form is much clogged with them, it should be well rubbed over with clean ley, or taken off and washed: in either case, before the pressman goes on again, it should be made perfectly dry by pulling several waste sheets upon it, in order to suck up the water deposited in the cavities of the letter. The pressman should accustom himself to look over every sheet as he takes it off the tympan: he will thus be enabled not only to observe any want of uniformity in the colour, but also to detect imperfections which might otherwise escape notice. In order to make perfect uniformity in the colour, the roller-boy should keep his ink well brayered out with the small roller, in proper quantities for the work in hand, and also should change his rollers well after taking ink, and at other times. The rollers are changed by moving the roller-handle slowly to the right and left, while the crank is being turned briskly with the left hand. Torn or stained sheets met with in the course of work are thrown out and placed under the bank. Creases and wrinkles will frequently appear in the sheets when the paper has been carelessly wet: these should be carefully removed by smoothing them out with the back of the nails of the right hand. If the frame of the tympan rub against the platen, it will inevitably cause a slur or mackle: this can easily be remedied by moving the tympan so as to clear the platen. The joints or hinges of the tympan should be kept well screwed up, or slurring will be the consequence. When the thumb-piece of the frisket is too long, it always produces a slur: this can be prevented by filing off a part of it. Loose tympans will at all times slur the work, and great care must therefore be observed in drawing them perfectly tight. The paper drying at the edges will also cause a slur: this may be remedied by wetting the edges frequently with a sponge. Slurring and mackling will sometimes happen from other causes: it will be well in such cases to paste corks on the frisket, or to tie as many cords as possible across it, to keep the sheet close to the tympan.