On the Latitude of the earth or of places. Chap. VIII.

Decorative drop cap L featuring a figure holding a globe.The latitude of a region or dwelling is a segment of the same meridian, defined by the vertex, or pole of the horizon, and the circle of the equator: and it is always equal to the altitude or elevation of the pole above the horizon; however, they differ from each other in a certain respect. For the elevation of the pole is the arc of the meridian intercepted between the pole of the world and the horizon. The latitude of a place, however, is the arc of the meridian contained between the zenith of the heads and the circle of the equator. These two portions of the meridian (as the author of the Sphere demonstrates) are equal. Therefore, the number of the latitude of the earth, both Northern and Southern, is written in solid and flat form by tens, as is usual, and similarly for longitude.

A circular diagram representing the celestial sphere or earth, labeled with cardinal directions (East, West, South, North), parallels, the Equinoctial, and the location of Antwerp. The diagram is surrounded by decorative foliage and birds.

Furthermore, so that nothing is missing from our calculation, we have intentionally placed this instrument, in which we have decided to show the equality of the latitude of some town and the elevation of the pole. You have, therefore, most pleasant Reader, a mobile horizon here, which you should either depress or elevate from the Northern part, according to what the number of degrees of the elevation of the pole demands for a certain elevation: and you will see that there are as many degrees of the same meridian depicted from the equinoctial circle to the zenith of the man as the arc of the same meridian between the pole of the world and the horizon contains.