Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/78

 comes from the reflection of the light of the Sun on the Superficies of the Earth and Sea; and that light is more clear, by how much the horns are lesse, for then the luminous part of the Earth, beheld by the Moon, is greater, according to that which was a little before proved; to wit, that the luminous part of the Earth, exposed to the Moon, is alway as great as the obscure part of the Moon, that is visible to the Earth; whereupon, at such time as the Moon is sharp-forked, and consequently its tenebrous part great, great also is the illuminated part of the Earth beheld from the Moon, and its reflection of light so much the more potent.

This is exactly the same with what I was about to say. In a word, it is a great pleasure to speak with persons judicious and apprehensive, and the rather to me, for that whilest others converse and discourse touching Axiomatical truths, I have many times creeping into my brain such arduous Paradoxes, that though I have a thousand times rehearsed this which you at the very first, have of your self apprehended, yet could I never beat it into mens brains.

If you mean by your not being able to perswade them to it, that you could not make them understand the same, I much wonder thereat, and am very confident that if they did not understand it by your demonstration (your way of expression, being, in my judgment, very plain) they would very hardly have apprehended it upon the explication of any other man; but if you mean you have not perswaded them, so as to make them believe it, I wonder not, in the least, at this; for I confesse my self to be one of those who understand your discourses, but am not satisfied therewith; for there are in this, and some of the other six congruities, or resemblances, many difficulties, which I shall instance in, when you have gone through them all.

The desire I have to find out any truth, in the acquist whereof the objections of intelligent persons (such as your self) may much assist me, will cause me to be very brief in dispatching that which remains. For a seventh conformity, take their reciprocal responsion as well to injuries, as favours; whereby the Moon, which very often in the height of its illumination, by the interposure of the Earth betwixt it and the Sun, is deprived of light, and eclipsed, doth by way of revenge, in like manner, interpose it self between the Earth and the Sun, and with its shadow obscureth the Earth; and although the revenge be not answerable to the injury, for that the Moon often continueth, and that for a reasonable long time, wholly immersed in the Earths shadow, but never was the Earth wholly, nor for any long time, eclipsed by the Moon; yet, neverthelesse, having respect to the