Who was responsible for building the first successful model glider as noted in the nonfiction book, The Wright Brothers: How They Invented the Airplane?

Sir George Cayley was a British baronet who studied the flight of birds and aeronautics in the early 1800s. The contraption Cayley devised had fixed wings, a tale, a fuselage and separate systems that would provide propulsion, lift, and control. In 1904, it was Cayley who built the first successful model glider.