As for example, wee will suppose of two places, whose di∣stance is to bee sought out, the former to be the Iland of Saint Thomas in Africa, the other the Iland Summatra in the East Indies, both situate directly vnder the Equatour; and there∣fore differing onely in Longitude. To expresse which, in this figure, let the first
Meridian from which the Longi∣tude is to be mea∣sured, be ABCD: the place where Saint
Thomas I∣land is seated, K: and the place of
Summatra, F. Thē subtracting AK, the Longitude of Saint
Thomas I∣land, being lesser, out of the Longi∣tude of
Summatra AE, the residue KE will shew the distance in degre
••s: which being multiplied by 60, and so conuerted into
Italian-miles, will shew how many miles the said places are distant the one from the other. As in this present example, wee finde the Lon∣gitude of Saint
Thomas Iland to bee 32 degrees 20 minutes of
Summatra, to bee 131 degrees: The lesser summe subducted from the greater; to wit, 32 degrees 20 minutes, out of 131; there will remaine 98 degrees 40 minutes: which being againe multiplied by 60, will produce 5920
Italian-miles, the true distance betwixt the said places.
2 Of two places in the same Hemispheare, situ∣ate without the Equatour; the distance may be knowne two wayes: either by the resoluti∣on of the Sphericall Triangle, or else by ta∣bles