Banner Image: Arus, Puerto Rico: Library On Wheels In Puerto Rico. A free Library on Wheels, the Carnegie “Book Mobile” is bringing romance and knowledge to thousands of children and adults in the rural areas of Puerto Rico. Stocked with 2,000 books each, three of the Bookmobiles reach areas on the 100-mile long island where “book learning” has been nonexistent. They carry a variety of adventure and travel books for youngsters and novels and biographies for the grown ups. The “bookmobiles” are rugged going when they explore he more distant villages towns where roads were built originally for oxcarts and mules. Photo at right, youngsters eagerly run towards the Bookmobile as it makes a stop in Arus in the sugar cane country along the South Shore.