Alfred Maul was a German engineer who, in 1904, successfully took aerial photographs of the ground from a height of 600 meters (2,000 feet) by attaching cameras to a black powder rocket, thereby creating the first instrumented sounding rocket. His 1912-model rocket carried a 20- by 25-centimeter photographic plate stabilized by a gyroscope. This method of reconnaissance was discontinued, however, upon the advent of airplanes.