b. 28 January 1886 Osaka, Japan
d. January 1976 Osaka, Japan
Yagi studied engineering at Tokyo Imperial University (now Tokyo University), graduating in 1910. For the next four years he taught at Engineering High School in Sendai, Honshu, then in 1914 he was sent to study resonance phenomena under Barkhausen at Dresden University. When the First World War broke out he was touring Europe, so he travelled to London to study under Ambrose Fleming at University College, London. Continuing his travels, he then visited the USA, studying at Harvard under G.W.Pierce, before returning to his teaching post at Sendai Engineering High School, which in 1919 was absorbed into Tohoku University. There, in 1921, he obtained his doctorate, and some years later he was appointed Professor of Electrical Engineering. Having heard of the invention of the magnetron, he worked with a student, Kinjiro Okabe; in 1927 they produced microwave energy at a wavelength of a few tens of centimetres. However, he is best known for his development with another student, Shintaro Uda, of a directional, multi-element ultrahigh frequency aerial, which he demonstrated during a tour of the USA in 1928. During the Second World War Yagi worked on radar systems. After his retirement he became Professor Emeritus at Tohoku and Osaka universities and formed the Yagi Antenna Company.
Yagi received various honours, including the Japanese Cultural Order of Merit 1976, and the Valdemar Poulsen Gold Medal.
b. 4 April 1821 Salisbury, New York, USA
d. 25 December 1868 New York City, USA
The son of a locksmith, Linus Yale Jr set out to become a portrait painter but gave this up in the 1840s to embark on the same profession as his father. He opened a shop of his own at Shelburne Falls, Massachusetts; his first products were keyoperated bank locks. The Great Exhibition of 1851 in London convinced him that any lock could be picked by someone with the necessary skill; he then turned his attention to the design of combination locks, designing the first doubledial bank lock in 1863. In 1868 he formed a partnership with John Henry Towne and his son Henry Robinson Towne to form the Yale Lock Manufacturing Company in Stamford, Connecticut, to make a patented key lock which incorporated a series of pin tumblers inside a cylinder. The principle of the pin-tumbler mechanism could be traced back to ancient Egypt; in Yale's cylinder lock, the serrations of the correct key raised the pin tumblers to the height at which the cylinder could turn, withdrawing the bolt. These cylinder locks made possible the use of smaller keys and became the foundation of the modern lock industry. Yale died soon after forming his partnership with the Townes.
b. 13 January 1842 London, England
d. 24 January 1932 London, England