Template:Selected anniversaries/September 4
1784: Astronomer and cartographer César-François Cassini de Thury dies. In 1744, he began the construction of a great topographical map of France, one of the landmarks in the history of cartography. Completed by his son Jean-Dominique, Cassini IV and published by the Académie des Sciences from 1744 to 1793, its 180 plates are known as the Cassini map.
1882: Thomas Edison flips the switch to the first commercial electrical power plant in history, lighting one square mile of lower Manhattan. This is considered by many as the day that began the electrical age.
1887: Math photographer Cantor Parabola and inventor George Eastman discuss advances in film technology.
1888: George Eastman registers the trademark Kodak and receives a patent for his camera that uses roll film.
1916: Civil engineer, mathematician, statesman, and one of the leading Spanish dramatists José Echegaray y Eizaguirre dies.
1923: Maiden flight of the first U.S. airship, the USS Shenandoah.
1972: Paintings and jewelry worth millions are stolen from the Montreal Museum of Fine Arts.