A railroad chronometer or railroad standard watch is a specialized timepiece that once was crucial for safe and correct operation of trains in many countries...

marked as Certified Chronometer or Officially Certified Chronometer. Outside Switzerland, equivalent bodies, such as the Japan Chronometer Inspection Institute...

A clock or chronometer is a device that measures and displays time. The clock is one of the oldest human inventions, meeting the need to measure intervals...

A marine chronometer is a precision timepiece that is carried on a ship and employed in the determination of the ship's position by celestial navigation...

Time was also "sold"[citation needed] to the railroads and was used in conjunction with railroad chronometers to schedule American rail transport. Early...

System Gantry Institution of Railway Signal Engineers Railroad chronometer Rail sabotage Railroad switch Railway semaphore signal Railway slide fence Signalling...

Clay Ball (1847–1922), American jeweller and watchmaker, Cleveland, railroad chronometer, Hamilton Watch Company. Henri Lioret (1848–1938), French watchmaker...

precision standards and a reliable timepiece inspection system for Railroad chronometers. Temperature-compensated balance wheels began to be widely used...

featuring a less accurate 21-jewel railroad grade movement.[citation needed] By 1970, 13,086 Hamilton Model 21 Marine Chronometers had been produced. In 1985...

Led to the adoption of stringent quality-control standards for railroad chronometers 1891 Bostian's Bridge train disaster, Statesville, North Carolina;...