1629: Christiaan Huygens, discoverer of the wave theory of light and of Saturn's moon Titan, was born. 1807: German chemist Jeremias Richter, who discovered law of equivalent proportions, died. 1828: first edition of Noah Webster's dictionary was published under the name "American Dictionary of the English Language." 1869: The airbrake was patented by George Westinghouse. 1894: The first public showing of Thomas Edison's kinetoscope took place. 1898: Harold Black, who developed the negative-feedback principle for amplifier design, was born. 1912: David Sarnoff picked up the distress call of the Titanic relayed from ships at sea: "S.S. Titanic ran into iceberg, sinking fast." 1918: U.S. First Aero Squadron engaged in America's first aerial dogfight with enemy aircraft over Toul, France. 1956: Ampex Corporation of Redwood City, CA, demonstrated the first commercial magnetic tape recorder for sound and picture. 1961: Manmade element Lawrencium (Lw, #103), was first produced. 2000: The Dow industrials plummeted 617 points and the Nasdaq composite index fell 355 points.