Complex sentence: The Cosmos Mercury was a fourteen-cylinder, twin-row, air-cooled, radial engine for aircraft designed by Roy Fedden of Cosmos Engineering and was built in the United Kingdom in 1917.
Split into simpler sentences: The Cosmos Mercury was a fourteen-cylinder twin-row air-cooled radial aeroengine. Designed by Roy Fedden of Cosmos Engineering, it was built in the United Kingdom in 1917.