Mary Ziegler supplies it. Ziegler, 33, a matter-of-fact woman who supports her art doing audiovisual production, calls her work at the Herron Test-Site gallery in Brooklyn, N.Y. (through Jan. 10), simply “mechanical sculpture.” Though that’s not as modest as, say, calling a piece by Giacometti (a sculptor she particularly admires) a “skinny metal person,” she does underestimate her stuff. At the gallery, Ziegler is exhibiting two new sculptures: the almost abstract wall piece “Myomortem” and the free-standing “The Way.” Both are amazingly poignant machines, meant to demonstrate what Ziegler calls the faulty, “incomplete systems” people devise to help them get through life in a big, scary universe.

Ziegler’s feel for the mechanical could have come from her electrical-engineer father, though he died when she was 1 year old. “Maybe I got some of this through his genes, I don’t know,” she muses. (She likes to use his old conduit tube cutter and level.) At the University of Wisconsin, where she got an art degree, her work was more about nature; one piece was a sculpture of a tree root coming up through the sidewalk. The shift to machinery (“They don’t teach this stuff in art school,” she says) came shortly after she arrived in New York in 1983 and was overwhelmed by the industrialization of the city. At first she lived near fashionable Soho, but later moved to what has been called “the new Bohemia,” the Williamsburg section of Brooklyn. Her new neighborhood could have only made her work grittier.

Ziegler’s mechanics are simple, but the results are subtle and complex. “The Way” is a kind of a concrete-and-metal landscape, on a steel table with a concrete roof, the whole piece a little taller than a person. The roof houses an electric motor that sends a few dangling metal thingamabobs on a slow horizontal circuit below. Another motor rotates small magnets behind two latex walls. The traveling whozits adhere momentarily to the magnets, twist and turn in apparent struggle, then break free. They do this over and over again, in endless variation. Whether we’re moved by Ziegler’s intended metaphors of “order and entropy, nature and culture, faith and knowledge” or we just like to watch the rhythmic permutations, “The Way” is fascinating.

“Myomortem” (loosely translatable as “muscular death”) is a sparer and crueler piece. It’s a big, wall-mounted prism, painted gun-metal blue, with a latex strip at its leading edge. Behind the strip, magnets rotate on a shaft. Bent staples and other metal jetsam cling to the latex and jerk spasmodically when the magnets pass underneath. What happens looks like the quick, desperate death throes of insects from a nature film. These things can’t really be alive, can they? But Ziegler’s work certainly is, no matter what self-effacing label she chooses to give it.