In the first shared photograph from the 1930s, two women with pin-curls have paused in the street: one sporting a two-shelf book case stacked with the slanting spines of books; the other with a volume in her gloved hands, head bowed toward the open pages.

There certainly is a rich history of people walking with books and of book collections made for traveling. Ues, walking libraries were a thing even in those decades.

Poet John Keats walked to the Lake District in Scotland in 1818, carrying Dante's Divine Comedy and the works of John Milton, for example. For conservationist John Muir's thousand-mile walk, he carried "a copy of Robert Burns’ poetry, Milton’s Paradise Lost, William Wood’s Botany, a small New Testament, a journal and a map." 

Carrying a full collection of books on a long trip would obviously have been tiring, but in 17th-century England, four individuals or families were lucky enough to own an expertly designed traveling library.

All it required were miniature books—about 50 gold-tooled, vellum-bound books, in fact, all bundled up into a larger wooden case bound in brown leather to look like a book itself, which are now held in the University of Leeds' special collections.

These traveling libraries were intended to be carried about by noblemen in their travels. For those who could afford such a custom-made treasure, kings, for example, traveling libraries were attractive. Napoleon Bonaparte, perhaps weary of lugging (or telling others to lug) "several boxes holding about sixty volumes each" of his favourite books, did commission his own traveling library.

For the less well-heeled, a different kind of traveling library soon became available. Schools are still visited by traveling booksellers, called book fairs or bookmobiles, that have their roots in traveling libraries from more than a century ago. These ambulatory book assemblages first moved on horse-drawn carts and then automobilies. Rural areas especially relied on the visiting collections. 

But there is another already potential walking library. An e-book reader that is reasonably priced and a pleasure to use will be the ultimate traveling library.