A still from Susan Robb's Warmth, Giant Black Toobs no. 3. a temporary installation that was up the afternoon of July 5 at Volunteer Park. Alice Wheeler

Last Thursday was quintessential July. I wouldn't have pegged Susan Robb for July, maybe October or April, something slyer, but last Thursday, she made a piece of quintessentially July art. It was hot and light and playful and right out on the lawn near the conservatory at Volunteer Park.

It was called Warmth, Giant Black Toobs no. 3, and an e-mail in advance promised that it would have "over twice the number of toobs as no. 2!" A photo of no. 2 was attached. In it, seven big stalks (toobs) like black baseball bats towered over the trees and over the white-dome top of the conservatory. They looked like they were taking themselves unfortunately seriously.

Photographs are such liars. The real toobs—a nice gender-crossing word—weren't serious at all. Staked to the ground at one end, they were flopping around in the wind like very conflicted, overly long phalluses. They were topped by knots that made their faces, when they came swinging in your direction, look like the butts of sausages.

Depending on how the light and wind hit them, their skin could change from flat black to chrome to mottled to wrinkled, like the sides of a tin can. When they went flying, they could be aggressive, or affectionate, or teasing. Occasionally, one of them, not caught by the wind, would stand inexplicably erect while the others flew diagonally like a clump of underwater reeds. People were picking favorites, but I only had eyes for the whole.

Robb told me she made them by tying one end of a 50-foot section of black plastic bag material closed, then opening the other end and letting the wind rush through to fill it up. The piece is solar-powered, by the same principle as in a hot-air balloon: as the sun heats the air, it rises, bringing its toob with it.

I'm always hearing from artists that they're worried about the environmental impact of what they make. (It's a good thing, but is it a Northwest thing?) Robb originally meant to build a career on large-format black-and-white photography, but turned away from it because of the chemicals she was dumping down the drain. (Her later, smaller color photographs, which featured in the discussion when Robb won The Stranger's first Genius Award for Visual Art, were of disgusting little sculptures of spit and food and her own hair, shot closely and printed beautifully.)

The other swaying-forest sculptures Robb has made—Seedlings (2001) and another piece at Kirkland Arts Center earlier this year—have relied on electrical technology. The toobs won't break down; they'll tear apart. (Which they did in an earlier incarnation on rougher grass.)

Robb can be a wild performance artist, but her interaction with the toobs was almost maternal, which is funny, considering she's a tenth the size of a single toob. She ran around the field politely asking people not to touch them. Annie Han of Lead Pencil Studio called out, "Don't get pummeled by those big black shafts!" At 5:30, the toobs came down. recommended