The Kitchen Hearth Kitchens by Rodale Press, Emmaus, Pa.; 1986; 147 pages; $12.95 paperback, $19.95 hardcover. Baths also by Rodale, 1986; 148 pages: $12.95 paperback, $19.95 hardcover. by Paul Hanke The premise of the Kitchens volume in Rodale's Home Design Series is that the "hearth" is not just a fireplace (or a room with one in it), but a focal point for the life of the occupants. This once-common nucleus, says the book's editors, has all but vanished from the contemporary American scene. Kitchens, the authors promise, is about "how to turn your kitchen into a hearth room." Practically speaking, this means designing a multipurpose kitchen/Great Room that can draw the family together again. But despite its being a fine offering on