Page:The Discovery of a World in the Moone, 1638.djvu/152

Rh B is the point of contingency, the distance betwixt A and B must bee supposed to be the twentieth part of the diameter which is an 100 miles, for so far are some enlightened parts severed from the common terme of illumination. Now the aggregate of the quadrate from AB a hundred, and BG a 1000 will bee 1010000, unto which the quadrate arising from AG must be equall according to the 47th proposition in the first booke of elements. Therefore the whole line AG is somewhat more than 1041004 [sic], and the distance betwixt HA must be above 4 miles, which was the thing to be proved.

But it may be againe objected, if there be such rugged parts, and so high mountaines, why then cannot wee discerne them at this distance, why doth the moone appeare unto us so exactly round, and not rather as a wheele with teeth?

Rh