The Johnson Collection of Contemporary Crafts at the Boston University School of Fine and Applied Arts, 855 Commonwealth Avenue, and the University of Massachusetts gallery, 100 Arlington Street, through December 23.

MAKING things by hand is so time-consuming that a craftsman has to pass his works off as Art. Then people will pay him the high wages accorded to Art, rather than the low wages paid for utilitarian things.

One summer, in Cambridge, I thought I'd make jewelry for money. I discovered that it took, say, four hours to make a pair of earrings. But a retailer wouldn't be able to ask more than six dollars for the pair. Which meant I would get three. I gave up the business. The alternative was to make the same thing over and over. which would have been efficient but boring. Of course, Alexander Calder and Salvador Dali sell their jewelry as Art, and get considerably more than six dollars per piece.

I suspect this is why the crafts in the Johnson Wax Company's collection show the artist's inclination for exploring media and being witty rather than making useful objects. In any case. the contrast between artists preoccupied with investigating material and those concerned with witty commentary livened up the show.

Unfortunately, Objects: USA, which originated at the Smithsonian, had to be split up in Boston because the Boston University gallery couldn't hold all 308 objects. But it's well worth the ride from Commonwealth Avenue to Arlington Street to see it all. The wooden pieces-all at the University of Massachusetts-were the ones I most coveted. Wendell Castle's "mahogany and silver leaf desk" was so curvingly sculptural. resting on an undulating snake of wood, that I didn't realize it was a desk until I read the wall label.

In contrast, J. B. Blunk's "seating sculpture" was only spottily polished for showing off redwood grains. Blunk took a huge chunk of redwood and hacked and carved it so at least four people can clamber over, sit on, put their hand through and lie down on it at once.

Likewise, metal work at the University of Massachusetts exulted in qualities that are uniquely metallic. Silver's smooth reflecting surfaces flowed into candelabras, cups and candlesticks. Gold jewelry often shone sleekly and most pieces looked almost too heavy to wear-and heaviness is an important part of gold's mystique.

HUMOROUS objects in both buildings fell into two categories: works of visual humor and three-dimensional drawings of literary witticisms. While plenty of fine, hard-to-handle glazes and well-made vessels were shown, the ceramicists (concentrated at Boston University) seemed to be the chief jokesters among craftsmen. In his six-foot high "Alice House Wall" Robert Arneson builds earthenware "stones" into a picture of a landscape with a ranch house. But its humor isn't in the subject-it's in the way the "stones" jostle and hug each other, and how the different blues, greens, oranges, pinks, and other unevenly applied glazes look next to one another.

Also at Boston University, Kim Newcomb's iridescent blown glass "Hot Dogs and Potato Chips" testifies to the influence of pop art on craftsmen. Blown glass potato chips really have to be seen to be visualized. The idea of doing this subject in such an elegant and delicate media. complete with paper napkins, plaster milk, and on an ordinary cafeteria tray really strikes the literary more than the visual funny bone. And Arneson's gawky earthenware bathroom sink is so literary that it even has a punchline-the brown splotch in the bowl is labeled "hard to get out stain."