ks, and in editions
published during the author's life the aid offered to the study of the
development of the final text by a long row of intermediate editions may
be very great.

Another instance in which imagination reinforces the more positive
interest a book may possess is in the case of editions which can be
connected with the origin, diffusion or development of printing. Piety
suggests that book-lovers should take a special interest in the history
of the art which has done so much for their happiness, and in this
respect they have mostly shown themselves religious. The first book
printed in any town is reasonably coveted by local antiquaries, and the
desire to measure the amount and quality of the work of every early
printer has caused the preservation of thousands of books which would
otherwise have perished. (See INCUNABULA.)

The financial side of book-collecting may be studied in Slater's
_Book-Prices Current_, published annually since 1887, and in
Livingston's _American Book Prices Current_, and in the same author's
_Auction Prices of Books_ (1905). While largely influenced by fashion
the prices given for books are never wholly unreasonable. They are
determined, firstly by the positive or associative interest which can be
found in the book itself, secondly by the infrequency with which copies
come into the market compared with the number and wealth of their
would-be possessors, and thirdly, except in the case of books of the
greatest interest and rarity, by the condition of the copy offered in
respect to completeness, size, freshness and absence of stains.
(A. W. Po.)

BOOK-KEEPING, a systematic record of business transactions, in a form
conveniently available for reference, made by individuals or
corporations engaged in commercial or financial operations with a view
to enabling them with the minimum amount of trouble and of dislocation
to the business itself to ascertain at any time (1) the detailed
particulars of the transactions undertaken, and (2) the cumulative
effect upon the business and its financial relations to others.
Book-keeping, sometimes described as a science and sometimes as an art,
partakes of the nature of both. It is not so much a discovery as a
growth, the crude methods of former days having been gradually improved
to meet the changing requirements of business, and this process of
evolution is still going on. The ideal of any system of book-keeping is
the maximum of record