Compelling tale of fact and fancy about crossing Niagara Falls

Crossing Niagara Play by Alonso Alegria. Directed by Andre Ernotte.

In the mid-19th century French aerialist Charles Blondin entered legend by crossing Niagara Falls on a 1,100-foot tightrope stretched 160 feet above the water. He then added variations of the feat - crossing blindfolded, or in a sack , pushing a wheelbarrow, turning somersaults, on stilts, and sitting down cooking an omelet. The climax occurred when he walked the tightrope with a man on his shoulders.

That - and a good deal more - is what ''Crossing Niagara,'' at the Manhattan Theater Club, is all about.

Peruvian playwright Alonso Alegria speculates imaginatively on what might have happened immediately before and during the two-man passage on Aug. 18, 1859 . Resting at his Niagara Falls hotel after the omeletmaking stunt, Blondin (Alvin Epstein) receives a visit from an intense and determined youth named Carlo (Paul McCrane). Carlo berates the celebrated Frenchman for having advertised a 12-egg omelet and then having used only eight in the culinary event. Worse than breaking his promise, chides Carlo, Blondin has been corrupting the purity of his aerial art with such crowd-pleasing hocus-pocus.

His bumptious indictment concluded, the young intruder tries to interest Blondin in a muscle-building regimen that he claims will enable the acrobat to leave the tightrope and walk in space. Before very long, Blondin has decided to cross Niagara with Carlo on his shoulders even though Carlo insists that the final decision shall be his.

In this mixture of fact and fanciful hypothesis, ''Crossing Niagara'' retells the story of what happens when the irresistible force of uncompromising naivete meets the not quite immovable object of professional sophistication. The unlikely encounter leads to an improbable friendship, a midair crisis, and a joyously shared triumph. Along the way, the seasoned tightrope walker and the unsquelchable novice share bits and pieces of their pasts, compare notes, and trade philosophical views. The play is saying that impossible things are the only things worth trying, that a lost courage can be regained, and that a shared victory beats a lonely triumph.

''Crossing Niagara'' appeals with its grace and flavor, its comic ebullience and provocative reflections. The performance staged by Andre Ernotte impresses with both its boldness and subtlety. Messrs. Epstein and McCrane exercise the kind of histrionic give and take that makes play-watching a pleasure.

Mr. Epstein's range and perceptiveness are physically abetted by his miming skills in the tightrope-walking scene. Mr. McCrane walks his own tightrope, steering Carlo along the thin line that divides obsessive fantasy from mild insanity as he fires the skeptical Blondin's imagination.

The integrity of a fully dimensioned production extends to Santo Loquasto's scenic artistry - in the comfortably stuffy hotel room of the opening scenes and the bare, misted stage suggesting (with the help of Jennifer Tipton's eerie lighting) the promontory overlooking the falls and the mid-passage of the actual crossing. Nor should one forget the incidental music, including the astral strings employed to heighten the aerial suspense.