Writers have often been attacked in print but relatively few have actually been pilloried. Perhaps the best known of these last is the gentleman pictured above, famous in his day as journalist, pamphleteer, spy, and novelist. Today he is remembered principally for a pair of books whose eponymous characters are respectively a shipwrecked sailor and a buxom beauty. Who is this colorful and perhaps criminal author?

All entries (one per person) must be clearly written on postcards and mailed to: Book Bag, The Washington Post, Washington, D.C. 20071, and must include complete return address and competition number. The winning entry will be the first correct answer drawn at random. Employes of The Washington Post Company and their families are not eligible to enter. Entries must be received no later than June 25th. The winner's name and city of residence will be announced in the July 5th issue of Book World. A Washington Post Book World book bag, and a children's book, will be sent to the winner.

Answer to Book Bag #421: The names of the musicians who wrote the following books about music are given after the books' titles: (1) School of Violin-Playing, by Leopold Mozart; (2) An Investigation of the True Way to Play the Clavier, by K.P.E. Bach; (3) Traite' de l'Instrumentation, by Hector Berlioz; (4) Principles of Orchestration, by Nicolas Rimsky-Korsakov; and (5) Traditional Harmony, by Paul Hindemith.

Winner: Yi-Ming Wang, Alexandria, Va.