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Rh the Art of Increaing it, and of aiting our Eyes by Telecopes can be carried.

, from a noble Confidence, that was very excuable conidering how trongly he was fir'd at the firt Dicoveries he made in an Art which he almot firt found out; Des Cartes, I ay, hop'd to dicover in the Stars, by the Aitance of Telecopes, Objects as mall as thoe we dicern upon the Earth. Sir Iaac has hown, that Dioptric Telecopes cannot be brought to a greater Perfection; becaue of that Refraction, and of that very Refrangibilty, which at the ame Time that they bring Objects nearer to us, catter too much the elementary Rays; he has calculated in thee Glaes the Proportion of the cattering of the red and of the blue Rays; and proceeding o far as to demontrate Things which were not uppos'd even to exit, he examines the Inequalities which arie from the Shape or Figure of the Glas, and that which aries from the Refrangibility. He finds, that the object Glas of the Telecope being Rh