Page:Philosophical Transactions - Volume 001.djvu/129

 should not appear in the like manner. But, I will determine nothing of any of these things. When I shall hereafter have made more frequent Observations of the Moon with my great Telescopes, in convenient time, I shall then perhaps learn more of it, than I know at present, at least it will excite the Curious to endeavor to make the like Observations; and it may be, others, that I have not thought of.

In. Of these Papers, Mr. Hook had intimated, that he would shortly discover a way of his, with a Plano-convex Glasse of a Sphære of 20. or 40. feet Diameter, without Veines, and truly wrought of that Figure, to make a Telescope, that with a single Eye-glass should draw 300, 400, yea 1000 feet, without at all altering the convexity: Monsieur Auzout returns this consideration, and offer upon it, which follows:

To perform (saith he) with a lesser Object-glass the effect of a great Telescope, we must find out a way to make such an Object-glass to receive as many Rayes as one will without their being sensibly distant from one another; to the end, that by applying to it stronger Eye-glass, there may be still Beams enough to see the Object, an to obliterate the small specks and imperfections of the Eye-glass. And if Mr. Hook hath this Invention, I esteem it one of the greatest, that can be found in the matter of Telescopes: If he please to impart it to us, we shall be obliged to him; and Rh