Canadian novelist Gibson has churned up a rich fuel of language for this tale of an Ontario farmer's fascination with--and life-long dedication to--the perfection of a perpetual-motion machine. While plowing in 1860, Robert Fraser goes over a huge bone: it turns out, with its neighbor bones, to belong to a mastodon. Word gets out of Fraser's find; in time he's paid a call by a huckster named Rochefoulcauld Hackett, who persuades him to let the mastodon be shown in Toronto and the States. Then, on his first rube's-visit to the big city, Fraser becomes enchanted with the idea of orrerys and perpetual-motion machines (as expounded by a crony of Hackett's); so, on returning home, he devotes all his time to building one of the latter for himself. But dreamers make questionable family men, of course: wife Mary languishes, consoling herself with food and yearnings for prodigal son Angus; the farm nearly goes bankrupt a number of times, saved by such providential/freak occurrences as a plague of wild pigeons (which Fraser adroitly exploits as a hunter's paradise). And all the while Fraser doggedly goes at his contraption, the machine growing ever more intricate. . . eventually factory-sized. Gifted with an unusual talent for natural description, a crammed universe bursting forth, Gibson is a little less adept at straightforward storytelling: his worked and learned style occasionally occludes the flow. (""A fiddle explores its thin and private descant; a wavering, ghastly sound, it seems all the dead voices want to speak. A crazy fiddle that bedevils even the birds. They click and grunt in their sleep. His son's feral tenor, the woman's diapason and Mary's gaze."") On balance, though, this is an intriguing, artful novel, peeling back wilderness to expose obsessive, large vision.