Day in Engineering History Archive - December 25

December 25

1741: The Centigrade temperature scale was devised by astronomer Anders Celsius. 1776: General George Washington and his troops crossed the Delaware River for a surprise attack against Hessian forces at Trenton, NJ. 1868: Linus Yale, inventor and manufacturer of locks, including the cylinder or pin-tumbler lock known by his name, died.  1988: Ernst Ruska, an electrical engineer who invented the electron microscope, was born. 1939: "A Christmas Carol," by Charles Dickens, was read on CBS radio for the first time. 1966: St. Elmo Brady, the first black man to earn a PhD in chemistry, died. 1977: Silent films legend Charlie Chaplin died.

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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.