Day in Engineering History Archive - April 15

April 15

Tax Day in the U.S.A. 1452: Leonardo Da Vinci was born. 1856: Conrad Hubert, founder of the Ever-Ready Battery Co., was born. 1707: Leonhard Euler, very familiar to all engineering students and renown for his photographic memory, was born. 1912: The British luxury liner RMS Titanic sank in the North Atlantic off Newfoundland less than three hours after striking an iceberg, killing 1,500 people. 1892: The General Electric Company was formed by the merger of the Edison Electric Light Co. and other firms. 1912: The time was spoken of by Einstein as the 4th dimension. 1923: Dr. Lee de Forest demonstrated phonofilm - his technique for putting sound on motion picture film. 1941: Igor Sikorsky made the first helicopter flight over one-hour duration in his VS-300. 1945: British and Canadian troops liberated the Nazi concentration camp Bergen-Belsen. 1952: The first B-52 Bomber prototype was tested in the air. 1964: The Chesapeake Bay Bridge-Tunnel (CBBT) opened, at the time the longest in the world at 17.6 miles shore-to-shore.

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Note: These historical tidbits have been collected from various sources, mostly on the Internet. As detailed in this article, there is a lot of wrong information that is repeated hundreds of times because most websites do not validate with authoritative sources. On RF Cafe, events with hyperlinks have been verified. Many years ago, I began commemorating the birthdays of notable people and events with special RF Cafe logos. Where available, I like to use images from postage stamps from the country where the person or event occurred. Images used in the logos are often from open source websites like Wikipedia, and are specifically credited with a hyperlink back to the source where possible. Fair Use laws permit small samples of copyrighted content.