Butler County Heritage Center, 119 W. New Castle St., with the new exhibit of the Jay Bee Miniature Circus, will be open from noon to 4 p.m. Wednesdays and 9 a.m. to noon Fridays from May through August, excluding legal holidays. Admission is $3 for adults, $1 for children ages 5 to 17, and free for children younger than 5. Call 724-283-8116.

Lowrie-Shaw House, built in 1828 by Walter Lowrie, Butler's only United States senator, at 123 W. Diamond St., will be open May through September from noon to 4 p.m. Mondays, Wednesdays and Fridays, except legal holidays. Admission is $3 for adults, $1 for children ages 5 to 17, and free for children younger than 5. Call 724-283-8116.

Harmony Museum, 218 Mercer St., Harmony, a National Historic Landmark, represents the town founded in 1804 by pacifist German Lutheran Separatists, and their Harmony Society, which became 19th century America's most successful communal group. The area was resettled in 1815 when Mennonite "second founder" Abraham Ziegler bought the society's holdings. The museum, open all year, presents these and other aspects of the area's history with guided tours offered from 1 to 4 p.m. daily except Mondays and holidays; reservations suggested for weekends and required for groups. Call 724-452-7341 or 888-821-4822, e-mail hmuseum@zoominternet.net., or visit the Web site, www.harmonymuseum.org.

<B>Heinz History Center</B>, 1212 Smallman St., presents "Pittsburgh Recast," featuring more than 50 pieces of work by members of the Pittsburgh Society of Illustrators through Sept. 7. Formed and Fired: Three Ceramic Traditions is on display in the History Center's first floor McGuinn Gallery through May 18. Hours are 10 a.m. to 5 p.m. daily, except holidays. Regular admission includes both the History Center and Sports Museum and is $9 for adults, $7 for senior citizens older than 61, $5 for students with ID and for children ages 6 to 18, and free for children younger than 6. Call 412-454-6000.<B>Pittsburgh Children's Museum</B>, 10 Children's Way, Allegheny Square, continues "Secrets of Circles," exploring the math, science and beauty behind the familiar shape. Regular hours are 10 a.m. to 5 p.m. Mondays through Saturdays and noon to 5 p.m. Sundays. Regular admission is $9 for adults, $8 for children ages 2 to 18 and senior citizens, and free for children younger than 2. Call 412-322-5058 or visit the Web site, www.pittsburghkids.org.<B>Carnegie Museum of Natural History</B>, 4400 Forbes Ave. in Oakland, continues Time Machines: Watches from the H.J. Heinz Collection through July 6. Admission is $15 for adults, $12 for senior citizens, $11 for children ages 3 to 18 and full-time students with ID, and free to children younger than 3 and Carnegie Museums members. Hours are 10 a.m. to 5 p.m. Tuesdays through Saturdays, 10 a.m. to 8 p.m. Thursdays, noon to 5 p.m. Sundays. C all 412-622-3131 or visit the Web site, www.carnegiemnh.org.