The steed that's fit for Britain's baby prince

Leave it to Britain's newest prince to have good horse sense.

At least, that's what Toronto's Monarchist League expects of young Prince William, born to a family of horse lovers.

So the league has commissioned a thoroughbred fit for a king - an old-fashioned rocking horse.

The $1,000 commission promises not only happy trails for the prince, but a booming business for woodcarver Gerard Boileau. Working in quiet obscurity with a carving talent developed only after his recent retirement, Mr. Boileau says demand for his polished wooden steeds has blossomed under the royal limelight.

Bloomingdale's department store chain has decided that what's good enough for the Windsors is good enough for its own discriminating customers. Boileau reports that the chain wants to market his horses next spring for a retail price of $900 - $300 more than he usually sells them for.

''This prince business is making it (his horse business) an overnight success ,'' Boileau says, observing with amusement that he would ''probably get to do a Tide commercial'' if he told anyone he uses the detergent to clean the real mane and tail hair he uses on his rocking horses.

But this French Canadian's humor is tempered with respect for the crown. ''My gift to the crown is to the symbol of the soul of a country. If the crown disappears, so does England.''

Further, Boileau shows a serious pride and a fascination in his carving talent that is richly apparent in his horses. The wooden rockers have been bought as art objects by several customers, transcending their functional use. (''If you saw the living room, you'd be proud to have your work there,'' Boileau says of one sale he made to a wealthy woman who wanted a horse for decoration.)

After losing his stage-rigging business in the late 1960s, Boileau says he took up ''paint by numbers'' to fill his time. When he discovered a carving knife that had belonged to his grandfather, he switched his hobby. He carved his first rocking horse without a single lesson two years ago as a gift, after finding he couldn't purchase the kind he remembers as a child.

Rubbing his hand over the first rough cuts on a block of native Canadian butternut wood that is to be the prince's first mount, Boileau glows with pride.

''I never saw the furniture in Buckingham Palace, but can you imagine Prince Philip examining this? It's going to have to be flawless,'' says Boileau, who is carving the horse at a booth at the Canadian National Exhibit here through mid-September.

Clamped to his workbench, the block of wood is slowly taking on rough equine proportions - 48 inches high at the head, 30 inches at the shoulder, and sturdy enough to hold even a 200-pound person.

Boileau estimates he will spend a month on the prince's horse rather than the two weeks it usually takes him to perfectly shape, sand, and varnish others.