As these quadrates are perfect segments of a large circle, they cannot be increased or diminished without destroying the truth of the curve. If the thin ends are pieced out with common quadrates, good justification will be rendered impossible; if they are shortened by cutting off, they are ruined. Bits of lead or short pieces of card between the curved surfaces are also wrong: they destroy that exact parallelism which is necessary for the security of the type. Very accurate justification of the outer extremities of the quadrates is also indispensable. If the curved surfaces are kept parallel, and the flat surfaces kept square, no difficulty will be found in using them, and they will prove a valuable aid in ornamental printing. LABOUR-SAVING CURVATURES, &c. [Illustration] Morris’s Adjustable Line Formers, or Labour-Saving Curvatures, do away with bent leads, plaster, wax, and other methods of making curved lines. Their economical advantages, and the neatness and exactitude of curve secured by their use, will be appreciated at a glance by all practical job printers. LEADS. Leads form an essential part of a printer’s outfit, since it is scarcely possible to set up a single page or job in which they may not be usefully employed; but their chief purpose is for spreading the lines apart so as to reduce the amount of matter in a page. Fine works are always thus leaded. They are usually cast by letter-founders in a long mould, and then cut to the required lengths. The bodies are regulated by Pica standard, and they are usually cast four, six, or eight to Pica, but are occasionally varied from one down to fourteen to Pica. Leads for jobbing purposes are now cut to graduated lengths, like labour-saving rule. FLOWERS AND BORDERS. The flowers and borders designed and cast at the present time far surpass any made by founders of earlier days. Their richness and variety enable printers to execute delicate and elaborate work, rivalling plate engraving, and afford a wide scope for the display of taste and artistic skill. The combination borders are especially valuable from being cast on uniform bodies, thus rendering them susceptible of a vast number of changes. The ancient practice of ornamenting pages with head and tail pieces of flowers and odd designs seems to be coming in vogue again, particularly in works printed in the old-style type. BRASS RULES. Rules are required mainly for table-work, and for pages which contain two or more columns. They are also useful in titles and jobs. Brass rules should never be more than type height, unless for perforating purposes, to divide railroad checks, &c. A shade lower would be often better, as the pressman would be enabled to bring off their impression more clearly. In table-work, the rule and figures should be separated by a lead, and all the rules should fit closely and accurately. The lately-invented BRASS LABOUR-SAVING RULE