In October 1884 an international conference held in Washington, D.C., adopted the meridian of the transit instrument at the Royal Observatory, Greenwich, as the prime, or zero, meridian.
The recommendation of the 1884 delegates was that there should indeed be an internationally recognised meridian from which to calculate longitude and a universal day, and that it should be the one passing through the Royal Observatory's transit instrument.
An international conference held in Washington, D.C., in 1884 designated "the meridian passing through the centre of the transit instrument at the Observatory of Greenwich as the initial meridian for longitude".
A four-inch equatorial, a three-inch transit instrument, and four pendulum clocks with two chronometers, were also procured from the observatory at Modena.
The final output data of all transit instruments are included in star or planetary catalogs.
Astronomical transit instruments are usually refractors with apertures of 15 to 20 cm (6 to 8 inches).
One of the most accurate astronomical transit instruments in the world is the U.S. Naval Observatory's 15-cm transit circle telescope (see photograph).
If the ground needed to be flat, the operator also determined where it needed to be leveled by using instruments on the transit similar to those used by carpenters.
Further, scientists who train their instruments on the transit can learn a great deal about the nature and composition of Venus' thick atmosphere.
Another musician, Dave Carroll, became so frustrated when he couldn't get any satisfaction after his instrument was damaged in transit that he filmed a music video, "United Breaks Guitars," where he sings: "You broke it, you should fix it You're liable, just admit it I should've flown with someone else Or gone by car 'Cause United breaks guitars".
