He played an important part in preparations for the war, in his
studies on gas and internal combustion engines, the science of flame
and explosions and in his study of the elastic hysteresis of metals.
At outbreak of war, Hopkinson was himself mobilised. The next four
years were the culmination of his life's work. He threw into the
war effort all his inventiveness, initiative and untiring energy.
He developed the idea of implanting blisters on ships hulls to absorb
the force of explosions from mines, as well as designing bombs and
equipment for aircraft.
Hopkinson photographed at Farnborough during
the First World War while serving as a major in the Royal Engineers.