There have been plenty of books published on the subject of tugboats in the past few years, sharing a cookie-cutter similarity - they're large, handsome, colorful, well-produced coffee-table volumes, which pretty much cover the same introductory material in the same glancing way. In all those regards and quite a few more, Virginia Thorndike's On Tugboats is a different sort of book. For starters, it's not large nor particularly handsome, and not all that well-produced - a standard paperback printed in black-and-white on paper that will probably not last for centuries. But then, it is a book crying out to be read, where coffee-table books ask merely to be seen.