THE BOOK ON THE BOOKSHELF By Henry Petroski Alfred A. Knopf 290 pp., $26
Who has not, at some point or other, marveled at the sheer multitude, variety, and convenience of books? It's amazing to realize how the invention of movable type unleashed a veritable explosion in the number of books and readers. But, as Henry Petroski observes in his new book, "The Book on the Bookshelf," very few of us have given much thought to the shelves on which books are kept.
A professor of engineering and history, Petroski loves to investigate the unfamiliar stories behind familiar objects, everything from "The Pencil" and "The Evolution of Useful Things" to the great bridges that were the subject of his "Engineers of Dreams."
Bookshelves may strike many of us as less of an invention than pencils, let alone bridges. Is it even, Petroski asks at the outset, "meaningful to ask why a bookshelf is horizontal and why books are placed vertically on it? Or are the facts so obvious as to need no explanation?"
As we read his history of books and their shelves from classical times to the present, we learn indeed that things were not always arranged in this manner.
Storing the scrolls on which Greek, Roman, and Hebrew texts were written involved different kinds of systems. Identified by a tag or ticket, they were stored on shelves rather like rolled up carpets at a carpet store, or sometimes stored standing on their ends in a contraption resembling a hatbox.
Only somewhere around the 2nd century AD did the codex begin to displace the scroll. So called, as Petroski tells us, because "they were covered with wood (codex means 'tree trunk' in Latin)," they were handier for several reasons: "Where an entire scroll might have to be unrolled to find a passage near the end, the relevant page could be turned to immediately in the codex." Unlike our modern book, the codex had no title on its spine, because books were not yet stored with their spines facing out.
In medieval times, books were rare and valuable items, kept in locked chests or cabinets. Even when access was made easier, and books were stored, lying on their sides, on shelves below slanted lecterns onto which they could be lifted for reading, each book was fastened to a long chain for security's sake.
Only in the 17th century did the shelves of upstanding books with which we're now so familiar become the norm. Thanks to printing, books were proliferating, and libraries soon began to worry about space. Another consideration for the designers of libraries, especially before the invention of electricity, was ensuring there would be enough natural light for reading.
By the late 20th century, Petroski notes, some university libraries, filled to - or beyond - capacity, have actually been encouraging library-users to check out (though not to steal) lots of books. More books in circulation means more shelf space for new arrivals.
The charm of this book lies in the way that it helps us take a fresh look at an old, long-familiar object, seeing it, as its various inventors and innovators did, for the first time. Almost no detail, however small, is unexamined. Sometimes, I must say, I found myself thinking that Petroski tells rather more than I, at least, ever wanted to know about bookshelves.
Nonetheless, this survey of the subject is probably definitive. If anyone can make bookshelves, well, maybe not sing, but at least speak, to us, Petroski is clearly the man.
*Merle Rubin reviews books regularly for the Monitor.
(c) Copyright 1999. The Christian Science Publishing Society