Template:Are You Sure/December 15
From Gnomon Chronicles
... engineer George Cayley (27 December 1773 – 15 December 1857) conducted pioneering research in aeronautics, investigating and codifying the dynamics of flight?
... engineer George Cayley (27 December 1773 – 15 December 1857) conducted pioneering research in aeronautics, investigating and codifying the dynamics of flight?