experiments in French naval submarine detection from her luxury yacht, the Liberty. In 2010 new research chronicled the episode, explaining how Matthews was frustrated in carrying out his aims. Later he propagated the idea of the "stratoplane" and joined the British Interplanetary Society. His reputation preceded him and the British Government was no longer interested in his ideas. Personal life Harry Grindell Matthews was the fifth husband of singer Ganna Walska: they married in 1938. He died of a heart attack on 11 September 1941. See also Samuel Alfred Warner References External links H. Grindell-Matthews, " Diabolic Rays", Popular Radio magazine, New York, Vol. 6, No. 4, August 1924, p. 149-154. Article in which Grindell-Matthews gives a limited description of the rays and what they can do. Harry Grindell Matthews website archive 1941 deaths 1880 births People from Winterbourne, Gloucestershire English inventors Pseudoscientific physicists Cinema pioneers British military personnel of the Second Boer War