Butler County Heritage Center, 119 W. New Castle St., celebrating the 150th anniversary of the birth of the oil industry with two exhibits, will be open from noon to 4 p.m. Saturday, the Fourth of July. Museum admission is $5 for adults, $2 for children ages 5 to 17, and free for those younger than 5. Call 724-283-8116.

Harmony Museum on Mercer Street in Harmony, is displaying "The First Shot," Deac Mong's painting depicting a "French Indian" firing the first shot of the French and Indian War at young Virginia Maj. George Washington near Harmony in 1753. The 5-foot by 4-foot painting is on loan to the Harmony Museum after being displayed at the Fort Pitt Museum in Pittsburgh. Regular guided tours are offered from 1 to 4 p.m. daily except Mondays and holidays; reservations are suggested for weekends and required for groups. Call 724-452-7341 or 888-821-4822, or visit the Web site, www.harmonymuseum.org.

<B>Heinz History Center</B>, 1212 Smallman St., features "Forbes Field: A Century of Memories" to commemorate the 100th anniversary of one of America's most famous ballparks. The exhibit celebrates the iconic park through a series of photographs, fan memorabilia, and never-before-seen artifacts from the park's illustrious history. Continuing is "Lincoln: The Constitution and the Civil War and Lincoln Slept Here" through January. History center hours are 10 a.m. to 5 p.m. daily, except holidays. Admission is $10 for adults, $9 for senior citizens age 62 and older, $5 for students with ID and for children ages 4 to 17, and free for children 3 and younger. Call 412-454-6000.<B>Pittsburgh Children's Museum</B>, 10 Children's Way, Allegheny Square, is hosting "Bob the Builder ¿ Project: Build It" through Sept. 27. Regular museum hours are 10 a.m. to 5 p.m. Mondays to Saturdays; and noon to 5 p.m. Sundays. Admission is $11 for adults; $10 for senior citizens and children ages 2 to 18, and free for children younger than 2. Call 412-322-5058 or visit the Web site, www.pittsburghkids.org.<B>National Aviary</B>, 700 Arch St., presents FliteZone, the aviary's outdoor free-flight bird show, included with admission. Visitors can also see the penguins in their new arena, Penguin Point. The aviary is open from 9 a.m. to 5 p.m. daily through Sept. 7. Admission is $10 for adults; $9 for senior citizens; $8.50 for children ages 2 to 12; and free for children younger than 2. Visit the Web site, www.aviary.org.<B>Phipps Conservatory and Botanical Gardens</B> in Schenley Park through Oct. 28 will host its first farmers market held from 2:30 to 6:30 p.m. Wednesdays on the lawn. About 20 vendors will feature local, certified organic and Certified Naturally Grown products including vegetables, meats, cheeses, eggs, bread, seedlings, honey, cut flowers, soap and perennials. Continuing is the new exhibition, "Life in the Gardens: Fräbel Glass at Phipps" through January. This exhibit features the imaginative artistry of German-born artist Hans Godo Fräbel, a founding father of modern glass sculpture. Phipps is open daily from 9:30 a.m. to 5 p.m. and until 10 p.m. on Fridays. Admission is $10 for adults, $9 for seniors age 62 and older and students with ID, and $7 for children age 2 to 18. Phipps members and children under 2 are admitted free. Call 412-622-6914 or visit www.phipps.conservatory.org.<B>Carnegie Science Center</B>, One Allegheny Ave. on the North Side, is open 10 a.m. to 7 p.m. Fridays and Saturdays and from 10 a.m. to 5 p.m. Sundays through Thursdays; closed holidays. Regular admission is $14 for adults and $10 for senior citizens age 62 and older and children 3 to 12. Parking is $3. Call 412-237-3400 or visit the Web site, www.carnegiesciencecenter.org.<B>Carnegie Museum of Natural History</B>, 4400 Forbes Ave. in Oakland, has extended "The Horse" exhibition's run through Sunday. "Tours" of Ancient Egypt are available in the Earth Theater. Continuing is "Dinosaurs in Their Time." Hours are 10 a.m. to 5 p.m. Tuesdays through Saturdays, with additional hours until 8 p.m. Thursdays, and noon to 5 p.m. Sundays. Closed major holidays, such as the Fourth of July. Regular admission, which includes the Carnegie Museum of Art, is $15 for adults, $12 for senior citizens, and $11 for students and children age 3 and older, and free for members and children younger than 3. Call 412-622-3131 or visit the Web site, www.carnegiemnh.org.