Can the wide-open vistas of the imagination that were unlocked by famed authors Edgar Rice Burroughs, Rudyard Kipling and Charles Dickens really be enjoyed on a 3.5-inch smartphone screen? Will the wit of Mark Twain’s “Roughing It” or the subtle comedy of manners found in Jane Austen’s “Emma” come across well when the device you’re reading those books on interrupts you for a phone call? Bookworms who are also Googlehounds are about to find out. The search company announced Thursday that it would begin offering a mobile version of Google Book Search.