Each entry occupies a line; each line is numbered from one up to such a number as the library has volumes.

The number of each line, called the accession number, is written on the first page after the title-page of the book described on that line.

The accession book is a life history of every book in the library.

It forms such a record as any business-like person would wish to have of property entrusted to his care.

It is also a catalog of all books in the library, and a useful catalog as long as the library is small.