Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/100

 It is so; and I have oftentimes wish'd that the Air would grow thicker, that I might be able to see that same light more plainly; but it ever disappeared before dark night.

You know then very certainly, that in the depth of night, that light would be more conspicuous.

I do so; and also more than that, if one could but take away the great light of the crescent illuminated by the Sun, the presence of which much obscureth the other lesser.

Why, doth it not sometimes come to pass, that one may in a very dark night see the whole face of the Moon, without being at all illuminated by the Sun?

I know not whether this ever happeneth, save onely in the total Ecclipses of the Moon.

Why, at that time this its light would appear very clear, being in a most obscure medium, and not darkned by the clarity of the luminous crescents: but in that position, how light did it appear to you?

I have sometimes seen it of the colour of brass, and a little whitish; but at other times it hath been so obscure, that I have wholly lost the sight of it.

How then can that light be so natural, which you see so cleer in the close of the twilight, notwithstanding the impediment of the great and contiguous splendor of the crescents; and which again, in the more obscure time of night, all other light removed, appears not at all?

I have heard of some that believed that same light to be participated to these crescents from the other Stars, and in particular from Venus, the Moons neighbour.

And this likewise is a vanity; because in the time of its total obscuration, it ought to appear more shining than ever; for you cannot say, that the shadow of the Earth intercepts the sight of Venus, or the other Stars. But to say true, it is not at that instant wholly deprived thereof, for that the Terrestrial Hemisphere, which in that time looketh towards the Moon, is that where it is night, that is, an intire privation of the light of the Sun. And if you but diligently observe, you will very sensibly perceive, that like as the Moon, when it is sharp-horned, doth give very little light to the Earth; and according as in her the parts illuminated by the Suns light do encrease: so likewise the splendor to our seeming encreaseth, which from her is reflected towards us; thus the Moon, whilst it is sharp-forked, and that by being between the Sun and the Earth, it discovereth a very great part of the Terrestrial Hemisphere illuminated, appeareth very clear: and departing from the Sun, and passing towards the *Quadrature, you may see the said light by degrees to grow dim; and after the