Today in Lab History: September 6, 1908- Louis Essen
Louis Essen was an English physicist who invented the quartz crystal ring clock and the first practical atomic clock. These devices were capable of measuring time more accurately than any previous clocks. He built a cesium-beam atomic clock, a device that ultimately changed the way time is measured.
Read more: http://www.laboratoryequipment.com/news/2012/09/today-lab-history