July 4

Today is Independence Day! 1753: Jean-Pierre-François Blanchard, who was the first to fly across the English Channel (in a balloon), was born. 1776: The amended Declaration of Independence, prepared by Thomas Jefferson, was approved and signed by John Hancock, President of the Continental Congress in America. 1817: Construction started on the Erie Canal. 1868: Astronomer Henrietta Swan Leavitt, who discovered the relationship between period and luminosity in Cepheid variables, was born. 1883: The first 3-wire central-station incandescent-lighting plant, built by the Edison Electric Illuminating Co., started operations in Sunbury, PA. 1883: Rube Goldberg, famous for his drawings of Mouse Trap-like contraptions, was born. 1903: President Theodore Roosevelt sent the first official message over the new cable across the Pacific Ocean between Honolulu, Guam, Midway and Manila. 1906: Vincent Schaefer, who invented cloud seeding for making rain, was born. 1922: Lothar von Richthofen, WWI flying ace and brother of the Red Baron, died. 1933: William Coolidge obtained a patent for the X-ray tube. 1934: Chemist Marie Marja Sklodowska Curie, discoverer of radium and polonium, died. 1960: The 50-star U.S. flag made its debut in Philadelphia, PA. 1976: Israeli commandos rescued the Entebbe Airport hostages held by Arab terrorists. 1997: The Mars Pathfinder, an unmanned space vehicle, landed on the Martian surface.