The Santos-Dumont Demoiselle was a series of aircraft built in France by the Brazilian aviation pioneer Alberto Santos-Dumont. They were light-weight monoplanes with a wire-braced wing mounted above an open-framework fuselage built from bamboo. The pilot's seat was below the wing and between the main wheels of the undercarriage. The rear end of the boom carried a tailwheel and a cruciform tail. The name is a contraction of mademoiselle and is a synonym for "jeune fille"—young girl or woman—but also the common name in French for a Damselfly. No. 19 The first aircraft of the type was the Santos-Dumont No. 19, which was built in 1907 to attempt to win the Grand Prix d'Aviation]] offered for a one kilometre closed-circuit flight. Powered by a 15 kW (20 hp) air-cooled Dutheil & Chalmers flat-twin engine mounted on the leading edge of the wing, it had a wingspan of 5.1 m. (16 ft 9 in), was 8 m (26 ft 3 in) long and weighed only 56 kg (123 lb) including fuel. It had a pair of hexagonal rudders below the wing on either side of the pilot, a forward mounted hexagonal elevator in front of the pilot and a cruciform tail which, like the boxkite-style canard surfaces on the earlier 14-bis biplane of 1906, pivoted on a universal joint to function both as elevator and rudder mounted at the end of a substantial single boom. There was no provision for lateral control. The undercarriage consisted of a pair of wheels in front of the pilot and a third behind, supplemented by a tailskid. Santos-Dumont made three flights on 17 November 1907 at Issy-les-Moulineaux. Later, Santos-Dumont made a number of modifications: he repositioned the engine, placing it below the wing in front of the pilot, fitted a different propeller and removed the forward elevator and rudders. No. 20 Santos-Dumont's next aircraft, the Demoiselle No. 20, was first flown in 1908, with an 18 kW (24-hp) Dutheil et Chalmers later replaced by a 22 kW (30 hp) Darracq-built liquid-cooled opposed twin engine of approximately 3.2-litre displacement. The fuselage consisted of three bamboo tubes forming the primary longerons, of about 5 cm (2 in) diameter, connected by oval steel tubes. For ease of transportation the bamboo tubes were divided into two sections, joined together by brass sockets. The parallel-chord wings had two spars made of ash and bamboo ribs<ref name=FL1909> Santos-Dumont "Demoiselle" [[Flight International|Flight,