Leads are designated as " - to-Pica," the number being that fraction of a Pica which the lead is, viz.: a 6-to-Pica lead is one-sixth of a Pica in thickness, or six, 6-to-Pica's, are equal to one Pica; four, 4-to-Pica's, are equal to one Pica, and so with other sizes or thickness of leads.
Leads of Nonpareil thickness and greater are called slugs, viz.: Nonpareil slugs, pica slugs, etc.
To estimate the quantity of type (solid) necessary to fill a given space, multiply the number of square inches by 5% (estimated weight in ounces, of one square inch of matter, including sorts in case), divide the product by 16 and the result will be the weight of type required. If leaded, a reduction in weight of type may be made from above.
Another rule is as follows: To ascertain the quality of type (solid) required for newspaper or boss. work, find the number 0r square inches to be set, and divide the same by 4, which will give the approximate weight of matter; to which 25 per cent should be added for "sorts," or dead letters remaining in the case. If the matter is to be leaded the weight may be reduced one-quarter.
There is considerable latitude in the use of proofreaders' marks and in methods of marking. Figure I shows the uncorrected proof as it goes to the reader for correction. Figure II gives an illustration of the proof marked and ready for marking. It is not to be assumed that there are ever as many errors as are here indicated, in ordinary matter. Matter set on the linotype from clear copy may not have but two or three minor errors. If hand setting is employed, there are generally more errors, depending much upon the character of the copy. For a concise treatment on marks the reader is referred to the title "Marks Used in Proof-Reading."
Referring to the numbered lines in Figure II, the following are the operations to be performed to correct the proof as marked:
Line 1. Bring the heading to the center; set in caps. Set name "Thomas Carlyle" in italics.
Line 2. Indent paragraph; delete apostrophe; set name "Burns" in small caps. Make cap TV lower case; insert y in place of marked letters.
Line 3. Turn inverted 7.
Line 4. Transpose indicated words; raise marked word to line with the rest; insert ed at end of line; turn hyphen.
Line 5. Delete d; transpose letters indicated.
Line 6. Insert u as indicated. Rearrange spacing for line as indicated by carets; insert hyphen at end of line.
Line 7. Clean.
Line 8. Insert o in place of letter marked. Insert o in place of inverted marked letter.