Despite several minor opening night glitchesit was Doug Henning's first outdoor production--his audience at the Merriweather Post Pavilion last night was left bewitched, bedazzled and bewildered. Body language for the night tended heavily toward slack jaws, wide-open eyes, applause and hands shooting up to volunteer for illusions grand and small alike. The capital of Henning's world of magic is Columbia, Md. . . . at least through Sunday.

Henning is not only an astouding illusionist--consider his sawing two women into halves and then reassembling . . . with mismatched halves--but a tremendous showman as well. His grinning enthusiasm propels him through thoroughly family fare, the kind that inspired such overheard kiddie comments as "How he do dat?" and "I wish I was a magic man." Adults, of course, responded with the more mature "How did he do that?" about a minute after they thought they had figured "that" out.

Henning, who succumbs to only a bit of cornball humor, paces his show with increasing degrees of bafflement and wonder-inspiring illusion. The best was a convincingly confounding levitation sequence and what may have been one of the quickest transformation/escapes on record.

Among other outstanding bits: sawing an assistant into four pieces, taking her apart and reassembling her correctly on the second try; dancing handkerchiefs with a mind of their own; a few passing-through tricks, like Henning passing through glass, a needle passing through a balloon, a little metamorphosis here and there. The best material seemed inspired by an unbounded world of imagination; the less-inspiring bits included some fairly standard sleight-of-hand.

One of Henning's consummate skills is in making it all look easy and natural, increasing the heights rather than the depths of his audience's perception. He's not above making magic accessible and even humorous at times, particularly in his good-natured dealings with volunteers.

Mention should be made of Clifford Guest, an Australian comedian who specializes in aural illusion. Working with nothing more than his voice, Guest created a military parade, a fox hunt, a space launch, even a set of bawling babies. Like Henning, he didn't suspend belief so much as he reinforced it. That kind of magic continues nightly through Sunday.