Joe Willis, science department chairman at Leggett Valley School, in Leggett, California, listed "the school Dumpster" as the best source of classroom freebies. We asked him to elaborate -- after washing his hands first:
"Science equipment, especially the stuff produced and marketed for schools, is too expensive! Plus, it tends to come with canned lessons that narrow the range of student exploration rather than expand it. Our solution has been to design and make our own equipment from discarded materials. My high school students, as well as my own two elementary-school-age children, regularly explore recycling bins and Dumpsters for things we can use for science experiments.
"For example, my own children and I make a marble run by gluing pieces of scrap wood and dowels to a 1-inch-by-10-inch board. Its uses range from entertainment and eye-hand coordination for kindergartners to more sophisticated explorations of acceleration and collisions for high school students. Students can be challenged to design a run with a set amount of materials that will result in the longest possible trip for a marble from top to bottom. I have also had students design similar runs entirely out of paper and glue or tape.
"The Jacob's Ladder was made of scrap wood and wire and a discarded transformer from a neon-light display. Kids love seeing 15,000-volt sparks climb the metal rods, and dozens of questions always arise, which provide great lead-ins for studying electricity. The idea for this was found on the Internet by my twelve-year-old son, who built it with my supervision.
"Naturally, any teacher supervising such inventions should be mindful of all safety considerations, and, when in doubt, should consult an expert. Remember, though, there is also a risk involved in not taking risks."