A salesman for the heavens wants to rope you in. (astronomer John Dobson)

"Come, come see the sun!" says the pitchman to a covey of tourists on the lakeshore. "I give you the sun, the whole sun and nothing but the sun!" He stoops to greet a little girl. "Want an elevator ride?" he asks, lifting her to the eyepiece of his telescope. "See the green balloon-? That's the sun. The dark spot there is a sunspot-a magneto-hydrodynamic zit on the face of the sun. It's as big as the Earth."

Ooh," says the little girl. He puts her down and invites others to peer into his telescope. While they take their turns he keeps up a stream of patter, about magnetism and gravity, the aurora borealis, radio in- terference, the special design of his telescope that allows people to view the sun without searing their eyeballs. As he speaks his hands describe theatrical arcs, his silver hair flutters in the wind, his voice rises and falls with studied modulation.

After oohs and wows, the people move on, but soon the pitchman spots fresh prey-a couple in Bermuda shorts-and hails them. "Come, come see the sun!"

Thus john Dobson, carny barker for the cosmos. Step right up, ladies and gentlemen, and look through his magical machines. He only wants to sell you the stars, and they won't cost you a dime. One-man revolution in telescope making john Dobson is an impoverished ex-monk, a maker of telescopes and an all-round astronomical gadfly. Though in his eighth decade, he has been described as '60s hippie who found his niche and stayed in it," a and some of his views on cosmology are, to say the least, unconventional. Yet his talents as a teacher and a booster are so luminous that even his critics have been known to refer to him as "a treasure, a national re-

" In the past decade or so he has revolutionized source. I amateur astronomy with his innovative ways of building telescopes that are big, simple and cheap, and thus has become a kind of cult hero to the community of amateur astronomers. "What he's done is extraordinary," says one keen amateur. "If you had told me 15 years ago that I'd be the proud owner of a 14.5-inch scope that I could load into a compact car, drive to a dark site and set up in 10 or 15 minutes I'd have called the men in white coats on you." But for all of his technical inventiveness Dobson has no real interest in the machinery of astronomy. What he cares about is spreading his special gospel. He is fond of quoting the New Zealand astronomer Graham Loftus: "What we need is a big telescope in every village and hamlet, and some bloke there with that fire vi I in his eye who can show something of the glory the world sails in." Dobson, God knows, has the fire, and he's driven to lead us to the glory. The night is full of wondrous things, huge things that span more of the sky than the moon: giant galaxies that look like pinwheels, clusters where stars swarm like bees, gauzy nebulae adrift in the Milky Way. There are stars revealed as twins locked in gravitational embrace, stars of red and blue and gold, stars that …