Day in Engineering History Archive - April 8

April 8

Heike Onnes Discovered Superconductivity - Please click here to visit RF Cafe.1779: Johann Schweigger, the physicist who invented the galvanometer, was born. 1861: Elisha Otis, inventor of the automatic safety brake for elevators, died. 1886: Carl Gassner was issued a German patent for the first "dry" cell, which used zinc as its primary ingredient. 1899: Martha Place became the first woman to be executed in the electric chair (a dubious claim for sure). 1911: Dutch physicist Heike Kamerlingh Onnes discovered superconductivity. 1952: Harry S. Truman/a> signed an executive order seizing U.S. steel mills to prevent strike of union steel workers (later ruled unconstitutional by the Supreme Court). 1973: Artist Pablo Picasso died of a heart attack. 1974: Hank Aaron hit his 715th home run, breaking Babe Ruth's record. 1997: Microsoft released Internet Explorer 4.0.

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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.