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
SS Archimedes lead to the adoption of screw propulsion by the Navy (see Legacy section below). With the conclusion of the Dover trials, "Archimedes" was placed at the disposal of Captain Chappell for a circumnavigation of Britain, which took place in July 1840. This voyage presented an opportunity to not only conduct further tests, but also to allow inspection of the technology by shipowners, engineers and scientists in ports throughout the country. "Archimedes" completed the 2006-mile voyage at an average speed in excess of 7 mph, and a maximum speed under ideal conditions of 10.9 mph. With the completion of this voyage,