Books are shown "IN" by the presence of the little cards, which appear as white underlinings to the number above; when "OUT," the slots are blank. The records of issue are kept by a charging system, which may be adapted for various purposes, as individual choice and fancy may direct.
The indicator invented by Mr. Bonner of the Ealing Library has a similar frame to that of the "Cotgreave," but the columns are a little wider. Each of the tin shelves holds a pentagon-shaped block, on each side of which a number is printed on a different coloured ground. The books are indicated "IN" by one colour, say red, and "OUT" by any of the other colours. Only one side of the pentagon can be seen by the public, and the difference of colour shows how long the book has been out, and how soon it may be expected back. All books issued during the first week of the month have, for example, a black number to the front; those issued during the second week, a blue number; the third week, a green number; the fourth week, a yellow number. No record of issue is kept in the indicator. That is done by the ordinary day-book, but the borrower's cards, which are of thin millboard, are slipped into the indicator frame, over the pentagon representing the book borrowed. The counter space required for a block of one-thousand indicator is about 2 feet.
In planning the lending library, attention must be given to the amount of counter space required for the display of the indicators. The "Duplex" takes 32 inches for each thousand numbers; the
