During the Romantic period, from the last decade or so of the eighteenth century to the 1830s, most prose fiction was considered subliterary, suitable mainly for children, women, and the lower classes. A few works were cherished by readers in all classes as childhood reading or “popular classics,” including generations-old chapbooks, such as Jack and the Giants, Valentine and Orson, and The Fair Rosamund, and longer works such as The Pilgrim's Progress, Robinson Crusoe, and The English Hermit. Don Quixote and the novels of Richardson, Fielding, Sterne, and Smollett were regarded as important works of literature. These and other earlier novelists were commercialized as “classics,” along with certain poets, dramatists, and belletrists, by publishers such as Harrison and Cooke after the ending of perpetual copyright in 1774. The spread of stereotype printing and sale of books in sixpenny “numbers” (or parts) from around 1800 gave a new plebeian and middle-class readership to earlier sentimental and pious novels such as The Pilgrim's Progress, Robinson Crusoe, Pamela, and The Vicar of Wakefield, and to picaresque identity-mystery romances such as Tom Jones. Most novels published during the period itself were dismissed by critics and readers as “the trash of the circulating library, ” to be rented and read quickly rather than purchased and kept.