(98)
and that of septalius must scatter them in the compass of three Inches. Some here do intend to make of them, yea and bigger ones; but we must stay till they be done, &c.
That eminent Astronomer of Dantzick, Monsieur Hevelius, writes to his Correspondent in London, as followeth:
What hath been done in the grinding of Optick glasses in your parts, and how those beginnings, mention'd by you formerly, do continue and succeed, I very much covet to hear. 'Tis now above ten Years, since I my self invented a peculiar way of grinding such Glasses, and reduced it also into practise; by which 'tis easie, without any considerable danger of failing, to make and pollish Optick glasses of any Conick Section, and that (which is most notable) in any dish of any Section of a Sphere: which Invention I have as yet discovered to none, my purpose being, for the improvement of Natural Knowledge, to describe the whole method thereof in my Celestial Machine, and to propose it to the Examination and Judgement of the Royal Society; not doubting at all, but they will finde the way true and practicable, my self having already made several Glasses by it, which many Learned Men have seen and tryed.
Monsieur Hugens, inquiring also in a Letter, newly written by him to a Friend of his in England, of the success of the attempts made by an Ingenious English Man for perfecting such Glasses, and urging the prosecution of the same,
