Page:Philosophical Transactions - Volume 001.djvu/75

 his New Observations of Saturn and Jupiter, made by means thereof.

First therefore, after that M. Auzout had raised some scruple against the Contrivance of Signor Campani for making Great Optick-Glasses without Moulds, by the means of a Turn-lath, he examines the Observations, made with such Glasses: Where, having commended Campani’s sincerity in relating what he thought to have seen in Saturn, without accommodating it to M. Hugen's Hypothesis, he affirms, that supposing, there be a Ring about Saturn, Signor Campani could not see in all those different times, that he observed it, the same Appearances, which he notes to have actually seen. For, having seen it sometimes in Trine Aspect with the Sun, and Oriental; sometimes, in the same Aspect, but Occidental; sometimes in Sextil Aspect, and Occidental, at another time, again in Trine and Oriental, this Author cannot conceive, how Saturn could in all these different times have no difference in its Phasis, or keep always the same Shadow; seeing that, according to the Hypothesis of the Ring, when it was Oriental, it must cast the Shadow upon the left side of the Ring beneath, without casting any on the right side; and when it was Occidental, it could not but cast it on the right side beneath, and nothing of it on the other.

Concerning the Shadow above, which Campani affirms to be made by the Ring upon the Body of Saturn, M. Auzout judges, that there could be no such Phænomenon, by reason of its Northern Latitude at the times, wherein the Observations were made, vid. in April 1663; in the midst of August, and the beginning of October, next following, and in April 1664, except it were in October, and the Shadow strong enough to become visible.

But as to the shadow below, he agrees with Campani, that it does appear, yet not as he notes it, seeing that it must be sometimes on the one side, sometimes on the other; and towards the Quadrat with the Sun it must appear biggest, as indeed he affirms to have seen it himself this year, insomuch that sometimes it seemed to him, that it covered the whole Ring, and that the Shadow, joyning with the obscure space between both, did interrupt the circumference of the Ring; but beholding it at other times in a cleer Sky, and when there was no Trepidation of the Air, Rh