Lawrence Hargrave was an engineer deeply interested in the idea of humans flying .During the 1880s, he studied the flights of birds and insects. Hargrave built many many model aircraft with flapping wings and some that uses propellors, but none would ever fly. He also built and flew many kites , and found that air moving over curved wings made the kites lift. In 1894, Hargrave was lifted 5 meter’s in the air by one of his box kites with two sets of curved wings. this news gave other inventors around the world new ideas to try. soon afterwards, the first biplanes were taking to the air