M.Dusing German & Austro-Hungarian Aero Engines of WWI. Vol.2 (A Centennial Perspective on Great War Airplanes 65)

Delfosse Motorenfabrik GmbH, Koln

  The technically skilled August Arthur Delfosse built his first motorcycle at the age of 15. It is well known that he made his first gliding tests with a self-built gliding apparatus in 1902 on the Mulheimer Heide in Cologne.
  In 1909 Delfosse built a monoplane which he demonstrated at the Cologne Flight Week and the Brussels Motor Show. He then founded the first aircraft engine factory in Germany in Riehl. While the frames and wings of the previously used flying machines were usually made of wood and bamboo cane, Delfosse already used seamless steel tubing, which was joined together using the autogenous welding process. The advantages of this innovation were that, despite the significant weight reduction, the frame and wings were more durable, and repairs could be carried out more easily. A further reduction in weight was achieved by using the three-cylinder 24 hp Delfosse engine specially designed for this aircraft.
  The Delfosse monoplane had a total weight of only 145 kg. The engine was in front, the propeller had a diameter of 2.10 m and was mounted directly on the engine axle.
  The company Aug. Arthur Delfosse Motorenfabrik GmbH was founded with the aim of supplying engines and accessories for the growing aircraft industry.
  The first advertisements of the Delfosse company appeared in 1910 in the magazine "Flugsport":
  "Complete flying machines, guaranteed to fly".
  These flying machines were of course equipped with engines from the company's own production.