Sentence:  Any ſphere revolving as on an axis, muſt have two points on its ſurface at the <WSD>extremities</WSD> of its axis, that do not revolve at all; theſe points, with reſpect to the Earth, are called its "poles". 
Meaning of the word marked with <WSD> tags:  The most extreme or furthest point of something. (from "c." 1400)