UFOs of the First World War. Phantom Airships, Balloons, Aircraft and Other Mysterious Aerial Phenomena, Paperback

Maxwell took off in his BE2C fighter but saw nothing unusual until 8.25 p.m. when, according to his report: `My engine was missing irregularly and it was only by keeping the speed of the machine down to 50 mph that I was able to stay at 10,000 feet.