EVERY WEDNESDAY EVENING at seven a changing of the guard takes place at the Taylor household on Capitol Hill. Jayne Bridge Taylor rushes out and Jim Taylor takes charge of James, 21 months, and Ashley, two months. Between baths and bedtime stories, he will also put together a supper to be eaten at 10, when Jayne gets home from her class in the art of the Oriental rug, offered by the Smithsonian Resident Associates.

"Over supper, I tell him what I've learned," says Jane Taylor.

Both Taylors became interested in rugs about three years ago when they bought two small Orientals through a sale sheet at the British Embassy, where Jayne worked.

"I'm not sure exactly what they are, but when I finish this course I will," says Taylor. "We decided we wanted Oriental rugs for our house. We didn't want anything modern, and we wanted rugs that wouldn't show the dirt and might appreciate."

Born in England, Taylor moved to Washington in 1972 and supported herself through dressmaking, making men's ties and catering, before landing a job at the British Embassy.

After the birth of a son in May 1978, Taylor devoted much of her time to her catering business -- a business that slowed down only momentarily when her daughter was born two days before Christmas. She also acts as the Washington representative of a Vermont dollmaker. Why, with a flourishing business and two children under two, did she decide to take a course?

"I like the outside stimulation," says Taylor, watching James drag a pull-toy across the Belouchi rug in the living room.

"And I want to be able to see rugs at auctions and know what it is I'm seeing -- to be able to tell what condition they're in and to give them a fair appraisal," says Taylor.

The eight-week course, which costs $44 for Smithsonian associates and $62 for nonmembers, covers such things as basic rug knots, dyes, history and dry cleaning.

"It's really a fascinating course," says Taylor. "The first week the instructor brought two rugs that were the same basic type but made in different countries -- and you'd never have known they were even similar. He explained that even such facts as where the sheep graze -- whether they graze in the mountains or down in the valley -- makes a great difference in the quality of the wool and the quality of the rug."