I46 OF THE LATITUDE AND LONGITUDE*

point of the meridian, parallel to the equator,all the places which lie under that parallel willbe equally distant from the equator, and conse-quently must have the tame latitude. Jt ap-pears, therefore, that by knowing the latitudeof a place only, we arc not from thence able toascertain its exact lituation. We can tell underwhat parallel it lies, and what is its distancefrom the equator ; but other considerations arenecessary to fix its precise position in that parallel,and to enable us to find it upon a map or globe.

Before we can do this, we must know thedistance of the place from a certain meridian, aswell as its distance from the equator. But asnone of these circles are, in their own nature,distinguishable from the rest, it will be necessaryto fix upon some one in particular, and agreet-0 refer all our computations to that. Suppose,for example, that we take any remarkable placeUpon the earth, and consider the meridianwhich passes over it, as the principal one : thismay then be called the first, and by noting thepoints where it cuts the equator, the distanceof- any place may be properly reckoned from itin degrees and minutes of that circle.

- - The choice of a first meridian has been amatter of considerable embarrassment both toastronomers and geographers, and even yet theyare not perfectly agreed in their determinations.The-.French make their first meridian p'h®i _ through