Lowrie-Shaw House, built in 1828 by Walter Lowrie, Butler's only United States senator, at 123 W. Diamond St., will be open noon to 4 p.m. Mondays, except closed April 14, and open as well from 10 a.m. to 2 p.m. Fridays. Admission is $3 for adults, $1 for those ages 5 to 17, and free for those younger than 5. Call 724-283-8116.

<B>Phipps Conservatory and Botanical Gardens</B> in Schenley Park concludes its Spring Flower Show on Sunday. Hours are 9:30 a.m. to 5 p.m. every day, except Christmas Day. Admission is $12.50 for adults, $11.50 for seniors age 62 and older and for students with ID, $7.50 for children ages 2 to 18, and free for children younger than 2. Call 412-622-6914.<B>Carnegie Science Center</B>, 1 Allegheny Ave., next to Heinz Field on the North Side, hosts Design Squad Weekend with fun engineering challenges for kids of all ages on Saturday and Sunday. All activities are free with general admission. Kites for Kids will take place April 26 and 27. "Bodies ... The Exhibition" continues through May 4; an extra fee is assessed for this display. Hours are 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 to the science center is $14 for adults and $10 for senior citizens age 62 and older and children 3 to 18. Parking is $3; people not visiting the science center pay more. Call 412-237-3400 or visit the Web site, www.carnegiesciencecenter.org.<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. Other exhibits include "Inside Peanuts: The Life and Art of Charles M. Schulz, through April 27, with assorted activities planned. 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.