Page:Mathematical collections and translations, in two tomes - Salusbury (1661).djvu/82

 instant, and its possible it may be a commixtion of my own conceipts, and those which I have sometime read in the fore-said Books, by which I well remember, that I was then perfectly satisfied, although the conclusions, at first sight seem'd unto me strange Paradoxes. We enquire Simplicius, whether to the making a reflection of light, like that which we receive from the Moon, it be necessary that the superficies from whence the reflection commeth, be so smooth and polite, as the face of a Looking-Glasse, or whether a superficies not smooth or polisht, but rough and uneven, be more apt for such a purpose. Now supposing two reflections should come unto us, one more bright, the other lesse, from two superficies opposite unto us, I demand of you, which of the two superficies you think would represent it self to our sight, to be the clearest, and which the obscurest.

I am very confident, that that same, which most forcibly reflected the light upon me, would shew its self in its aspect the clearer, and the other darker.

Be pleased to take that Glasse which hangs on yonder Wall, and let us go out into the Court-yard. Come Sagredus. Now hang the glasse yonder, against that same Wall, on which the Sun shines, and now let us with-draw our selves into the shade. See yonder two superficies beaten by the Sun, namely, the Wall and the Glasse. Tell me now which appears clearest unto you, that of the Wall or that of the Glasse? Why do you not answer me?

I leave the reply to Simplicius, who made the question; but I, for my own part, am perswaded upon this small beginning of the experiment, that the Moon must be of a very unpolisht surface.

What say you Simplicius, if you were to depaint that Wall, and that Glasse fastened unto it, where would you use your darkest colours, in designing the Wall, or else in painting the Looking-Glasse.

Much the darker in depainting the Glasse.

Now if from the superficies, which represents it self more clear, there proceedeth a more powerful reflection of light, the Wall will more forcibly reflect the raies of the Sun, than the Glasse.

Very well, Sir, have you ever a better experiment than this? you have placed us where the Glasses doth not reverberate upon us; but come along with me a little this way; how, will you not stir?

You perhaps seek the place of the reflection, which the Glasse maketh.

I do so.