SECTION V. 233 Lion ; for where the complements of any too arches are equal, the arches themselves must also be equal. As every place is supposed to have its proper meridianor line of longitude, so every place has its proper line of, latitude which is a parallel to the equator. By these parallels the eye is directed to the degree of the latitude ofthe place marked mi the meridian, either on globes or maps. By the longitude and latitude being given you may find where to fix any place, or where to find it in any globe or map : For where those two supposed lines (viz.) the line of longitude and parallel of latitude cross each other, is the place enquired. So if you seek the longitude from Ferro, 20 degrees, and the latitude 511 degrees, they will spew the point where London stands. Those parallels of latitude which are drawn at such distan- ces from each other near and nearer to the poles, as determine the longest days and longest nights of the inhabitants to be half an hour longer or shorter, include so many distinct climates, which are proportionally hotter or colder according to their distance from the equator. Though it must be owned that we generally use the word climate in a more indeterminate sense, to signify a country lying nearer or farther from the equator, and conse- quently hotter or colder, without the precise ideaof its longest day deing just half an hour shorter or longer than in the next country to it. The latitude is never counted beyond 90 degrees, because that is the distance frein the equator to the pole: The longitude arises a any number of degrees under 360, because it is counted all round the globe. Ifyou travel never so far directly towards east or west your latitude is still the same, but longitude alters. If directly toward north or south, your longitude is the same, but latitude alters. If you go obliquely, then you change both your longitude and latitude. The latitude of a place, or the elevation of thepole above thehorizon of that place, regards only the distance northward or southward, and is very easy to be determined by the sun or stars with certainty, as Sect. XX. Prob. VII, and IX. because, whets they are upon the meridian they keep a regular and known dis. tance from the horizon, as well as observe their certain and rege. lar distances from theequator, and from the two poles, as shall be shewn hggreafter : So that either by the sun or stars (when you travel ttßrthward or southward) it may be found precisely how much your latitude alters. But it is exceeding difficult to determine what is the longi- tude of a place, or the distance of any two places from each other eastward or westward by the sun or stars, because they are always moving round from east to west.
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