Archimedes' screw pipe does not need to be perfectly watertight, as long as the amount of water being scooped with each turn is large compared to the amount of water leaking out of each section of the screw per turn. If water from one section leaks into the next lower one, it will be transferred upwards by the next segment of the screw. In some designs, the screw is fused to the casing and they both rotate together, instead of the screw turning within a stationary casing. The screw could be sealed to the casing with pitch resin or other adhesive, or
Archimedes-lab.org and the development of creativity. Here's a quote from Scientific American (May 27, 2003): "This virtual lab borrows the empirical spirit and creative curiosity that Archimedes brought to his work and invites visitors to explore with the same expectations for mind-blowing discovery." Archimedes-lab.org has won several awards from scientific and educational publications, including a Scientific American Web Award in 2003, the National Council of Teachers of Mathematics Web Award, and a mention in MERLOT, the Multimedia Educational Resource for Learning and Online Teaching and in The DO-IT Center, the Disabilities, Opportunities, Internetworking, and Technology Center. Archimedes-lab.org Archimedes-lab.org is a free