387.  Another circumstance omitted to be noticed in the first edition relates to what is technically called the overplus, which may be now explained.  When 500 copies of a work are to be printed, each sheet of it requires one ream of paper.  Now a ream, as used by printers, consists of 21 1/2 quires, or 516 sheets.  This excess of sixteen sheets is necessary in order to allow for ’revises’—­for preparing and adjusting the press for the due performance of its work, and to supply the place of any sheets which may be accidentally dirtied or destroyed in the processes of printing, or injured by the binder in putting into boards.  It is found, however, that three per cent is more than the proportion destroyed, and that damage is less frequent in proportion to the skill and care of the workmen.

From the evidence of several highly respectable booksellers and printers, before the Committee of the House of Commons on the Copyright Act, May, 1818, it appears that the average number of surplus copies, above 500, is between two and three; that on smaller impressions it is less, whilst on larger editions it is greater; that, in some instances, the complete number of 500 is not made up, in which case the printer is obliged to pay for completing it; and that in no instance have the whole sixteen extra copies been completed.  On the volume in the reader’s hands, the edition of which consisted of 3000, the surplus amounted to fifty-two—­a circumstance arising from the improvements in printing and the increased care of the pressmen.  Now this overplus ought to be accounted for to the author—­and I believe it usually is so by all respectable publishers.

388.  In order to prevent the printer from privately taking off a larger number of impressions than he delivers to the author or publisher, various expedients have been adopted.  In some works a particular watermark has been used in paper made purposely for the book:  thus the words ‘Mecanique Celeste’ appear in the watermark of the two first volumes of the great work of Laplace.  In other cases, where the work is illustrated by engravings, such a fraud would be useless without the concurrence of the copperplate printer.  In France it is usual to print a notice on the back of the title page, that no copies are genuine without the subjoined signature of the author:  and attached to this notice is the author’s name, either written, or printed by hand from a wooden block.  But notwithstanding this precaution, I have recently purchased a volume, printed at Paris, in which the notice exists, but no signature is attached.  In London there is not much danger of such frauds, because the printers are men of capital, to whom the profit on such a transaction would be trifling, and the risk of the detection of a fact, which must of necessity be known to many of their workmen, would be so great as to render the attempt at it folly.

389.  Perhaps the best advice to an author, if he publishes on his own account, and is a reasonable person, possessed of common sense, would be to go at once to a respectable printer and make his arrangements with him.