Circle of latitude Circle of latitude A circle of latitude on Earth is an abstract east–west circle connecting all locations around Earth (ignoring elevation) at a given latitude. Circles of latitude are often called parallels because they are parallel to each other; that is, any two circles are always the same distance apart. A location's position along a circle of latitude is given by its longitude. Circles of latitude are unlike circles of longitude, which are all great circles with the centre of Earth in the middle, as the circles of latitude get smaller as the distance from the Equator increases. Their length
Gaithersburg Latitude Observatory one of the four original observatories built by 1899 — tracking the degree of "wobble" occurring on the earth's north-south axis and resultant variation of latitude. The Observatory — along with observatories in Cincinnati, Ohio; Ukiah, California; Mizusawa, Japan; Charjui in Russian Turkestan; and Carloforte, Sardina, Italy — performed in concert to carry out a coordinated program of star observation designed to investigate and calculate the degree of earth "wobble" or latitude variation. On the grounds of the Gaithersburg Latitude Observatory stands a plaque that reads: This small framed structure played a key role in the scientific investigation of the