A compound-complex sentence combines the compound and the complex sentence. The compound part means that it has two or more complete sentences. The complex part means that it has at least one incomplete sentence.
Archimedes' principle. Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces and acts in the upward direction at the center of mass of the displaced fluid. Archimedes' principle is a law of physics fundamental to fluid mechanics. It was formulated by Archimedes of Syracuse.
Archimedes Death Ray: October, 2005. See video of the experiment (.mov, 7.0 Mb version, 25.3 Mb version, or 69 Mb version) as seen on the TV program the Daily Planet. You may also want to read the FAQ or other publicity about the test. We also did a follow up experiment with the Mythbusters. Click on image thumbnails to see larger images. Ancient Greek and Roman historians recorded that during the siege of Syracuse in 212 BC, Archimedes (a notably smart person) constructed a burning glass to set the Roman warships, anchored within bow and arrow range, afire.