FAMILY HISTORY can be a burden - or a source of creative strength, as Roger Burford Mason demonstrates in his second collection, The Beaver Picture & Other Stories (Hounslow, 165 pages, $15.95 paper). Burford Mason emigrated from England to Canada in 1988, but his family`s transatlantic links date back to early in this century. The connections between the old world and the new seem to fascinate him, and the best stories here are the ones that use a graceful blend of history and fiction. In "Finding Adam Wilson," the narrator sets out to track down a lost relation only to find that the past is more sinister and more complex than he had imagined. "Discovering My Father," on the other hand, is a son`s tribute to a father who was reluctant to reveal much of himself. When the narrator states, "Almost everything I know about my father, I learned by accident," the scene is set for revelations that are at once surprising and touching. Not all the stories succeed. In "The Harrington Woman," Burford Mason provides a good setting and strong characters, but his waffling on motivation makes the denouement less credible. The title story, however, is itself worth the cover price. "The Beaver Picture" is set in post-First World War England, and chronicles the separate fates of an unhappily married couple. After the husband emigrates to Toronto, his wife concentrates her emotional energies on embroidering an elaborate picture of a beaver - the symbol of Canadian industry and ingenuity, as Burford Mason reminds us. As the beaver picture takes form, the marriage gradually disintegrates. Roger Burford Mason`s elegant understatement makes this my choice for best short story of the season.