Hoover 'Keymatic' model 3224 washing machine, designed and developed by Hoover Limited engineering laboratories, Perivale, Middlesex, and made by Hoover (Washing Machines) Limited, Merthyr Tydfil, Wales, with motors made at Hoover (Electric Motors) Limited, Cambuslang, Scotland, 1963 Hoover 'Keymatic' washing machine Domestic Appliances 1963
Model of open oscillator with spherical radiators used by Heinrich Hertz, 1949 Radio Communication 1949