O.Thetford, P.Gray German Aircraft of the First World War (Putnam)

Gotha G VI
  Based on the standard Gotha G V wing cellule, the G VI was probably the world's first asymmetric aircraft. The fuselage, offset to port, housed a normally mounted engine in the nose driving a tractor airscrew, the nacelle to starboard housing the other engine driving a pusher airscrew. After some successful flights, the machine was wrecked and was developed no further. Engines, two 260 h.p. Mercedes D IVa. Span, 23.7 m. (77 ft. 9 1/4 in.). Length, 12.4 m. (40 ft. 8 1/4 in.). Area, 89.5 sq.m. (967 sq.ft.).