494,938. 'Cooling cylinders; radiators for aircraft and motor vehicles. HULSEBOS, W., and NAAMLOOZE VENNOOTSCHAP HULSEMO. April 28, 1938, No. 12758. [Class 7 (ii)] [Also in Group XIII] In an internal-combustion engine, having cylinders 2 arranged parallel to the driving shaft and cooled by liquid circulation, the radiators 5 are located in an annular space between the engine casing 1 and a cowling 11. The radiators extend round the two sides of the casing from a top header, receiving the cooling liquid through a pipe 10, to a bottom header connected to a circulating pump. Cooling air is received, either axially as shown at the top of the Figure, the flow being controlled by shutters 14 adjustable over the exit ports, or partly axially and partly through louvres 15, baffles 16a deflecting the air through the respective radiators.