above the sea. Samuel Franklin Cody was the most successful of the man-lifting kite pioneers. He patented a kite in 1901, incorporating improvements to Hargrave's double-box kite. He proposed that its man-lifting capabilities be used for military observation. After a stunt in which he crossed the English Channel in a boat drawn by a kite, he attracted enough interest from the Admiralty and the War Office for them to allow him to conduct trials between 1904 and 1908. He lifted a passenger to a new record height of 1,600 ft (488 m) on the end of a 4,000 ft (1,219 m) cable. The War Office officially adopted Cody's War Kites for the Balloon Companies of the Royal Engineers in 1906, and they entered service for observation on windy days when the Companies' observation balloons were grounded. Like Hargrave, Cody strung up a line of multiple kites to lift the aeronaut, while greatly improving on the details of the lifting gear. He later built a "glider kite" which could be launched on a tether like a kite but then released and flown back down as a glider. The Balloon Companies were disbanded in 1911 and were reformed as the Air Battalion of the Royal Engineers, forerunner of the Royal Air Force. Roald Amundsen, the polar explorer, commissioned tests on a man-lifting kite to see whether it would be suitable for observation in the Arctic, but the trials were unsatisfactory and the idea was never developed. Modern kiting A series of innovations in the late 20th and early 21st century revitalized interest in the field of people being lifted by kites for recreation. The growth of water skiing especially led to the idea of adding a kite, so that the skier could take off and fly. From the late 1950s, flat kites began to be used to propel the skier, while other kites were fitted with seats on the line pulled by a motorboat. The skier was able to marginally control these unstable flat kites by using swing seats that allowed their entire body weight to effect pitch and roll. Through the 1960s the Rogallo wing was developed and many early types such as Australian John Dickenson in Australia Bill Bennett's Delta Wing series were developed as manned kites. John Worth adopted the cable-stayed triangle control frame at several scales in stiffened Rogallo wing kite glider and powered versions. John Dickenson used