In 1904, the Brazilian pioneer aviator, Alberto Santos-Dumont complained to his friend Louis Cartier of the unreliability and impracticality of using pocket watches while flying. Cartier designed a flat wristwatch with a distinctive square bezel. This watch was favored not only by Santos-Dumont himself but also by many other customers. The "Santos" watch was Cartier's first men's wristwatch. In 1907, Cartier signed a contract with Edmond Jaeger, who agreed to exclusively supply the movements for Cartier watches. Among the Cartier team was Charles Jacqueau, who joined Louis Cartier in 1909 for the rest of his life, and Jeanne Toussaint, who was Director of Fine Jewellery from 1933.