"Mr. Wizard," TV's first science show for kids, made its debut this day in 1951. Host Don Herbert entertained as he explained 'the way things worked.? Today, many of us who were viewers still are fascinated with the role science plays in our everyday lives -- including home maintenance. Take icicles for instance. Have any hanging from your roof? They might look pretty, but they're not good. Icicles are formed by water runoff caused when warm air escapes into your attic and melts the snow on the roof above it. The water runs down and refreezes when it hits the cold exposed overhangs. Some become icicles; the rest builds up on top and becomes an ?ice dam.? The ice dam soon holds back the water runoff and sends it up under shingles, where leaks can begin. To prevent ice dams, keep attics cold, seal warm-air leaks from below, have sufficient attic insulation and be sure roof and eave vents are clear and open. You'll prevent potential leaks, avoid falling icicles and make Mr. Wizard proud of what you've learned. And that's the On The House tip for today.