The Meridian Circle Telescope
Think of today’s technologically advanced means for determining time and location, such as cesium clocks and the GPS satellite network. The Meridian Circle Telescope (MCT) was the 1800s equivalent.
The MCT was designed for one scientific function with two purposes. Its function was measuring the position of stars and other celestial bodies with extreme precision. And, because the precise position of a star is determined by two coordinates—its “declination,” i.e., its north-south position, and its “right ascension,” which is determined by the hour-minute-second at which it crosses the meridian—its position can also be used to set exact time. So, the MCT was a celestial-positioning tool and a time-setting tool of tremendous accuracy.