Template:Selected anniversaries/September 28: Difference between revisions

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||1858: Donati's comet (discovered by Giovanni Donati, 1826-1873) became the first to be photographed. It was a bright comet that developed a spectacular curved dust tail with two thin gas tails, captured by an English commercial photographer, William Usherwood, using a portrait camera at a low focal ratio.  
||1858: Donati's comet (discovered by Giovanni Donati, 1826-1873) became the first to be photographed. It was a bright comet that developed a spectacular curved dust tail with two thin gas tails, captured by an English commercial photographer, William Usherwood, using a portrait camera at a low focal ratio.  


||1860: Paul Ulrich Villard born ... chemist and physicist.
||1860: Paul Ulrich Villard born ... chemist and physicist. Pic.
 
||1803: Guglielmo Libri Carucci dalla Sommaja dies ... mathematician and academic. Pic.


||1889: The first General Conference on Weights and Measures (CGPM) defines the length of a meter as the distance between two lines on a standard bar of an alloy of platinum with ten percent iridium, measured at the melting point of ice.
||1889: The first General Conference on Weights and Measures (CGPM) defines the length of a meter as the distance between two lines on a standard bar of an alloy of platinum with ten percent iridium, measured at the melting point of ice.

Revision as of 07:02, 7 February 2019