James Duff Brown, Manual of Library Economy
“ It has been definitely ascertained that 6 per cent. of the population of the average town become borrowers. For this number the average stock of books provided in lending libraries is three per borrower. Books are kept out on an average ten days each, or twelve days non-fiction, eight days fiction. In a year of 306 days each borrower will read about thirty books. Here, then, is a basis from which to start in providing accommodation for a lending library. If a town has 50,000 inhabitants, it will attract 3000 borrowers, who will require 9000 volumes as a minimum lending stock. ”
