[3] However his arrival there was delayed by the war, as he spent some time with Archibald Hill, applying a scientific approach to anti-aircraft gunnery.
[3] During the time he spent with the Anti-Aircraft Experimental Section of the Munitions Inventions Department he gained experience of scientific research.
[4] In 1924 he married Dora Amy Royle de Bude and then started work for Oxford University Press as a travelling salesman selling technical books.
[2] In 1934 he married Franziscka Zarniko who he met in the USSR whilst visiting the Ukrainian Institute of Physics and Technology (UPTI) in 1932.
Crowther remained in correspondence with the Russian physicist Boris Hessen following his visit to London as part of the Soviet delegation to the Second International Congress of the History of Science.