▼OI-. XVI.] PHILOSOPHICAL TRANSACTIOWS. 331 



in the distinct-base of the middle eye-glass is erect, and is so brought to the 

 eye by the eye-glass ; the eye-glasses themselves, in neither case, having any 

 thing to do with the erecting or inverting, but merely in representing in the 

 same posture the species immediately before them. 



The French problem therefore should not have broken a telescope of four 

 convex-glasses into four pieces, but into two, and then the case would have 

 been plain ; whereas by breaking it into four perspective-glasses, they attribute 

 that to two of them, which neither of them effects, viz. inverting and erecting. 

 Hence then, in general, one convex-glass, as posited in a telescope, inverts ; 

 the second, that is the first eye-glass, does nothing towards erecting or revers- 

 ing, but represents the image as it is in the distinct-base of the object-glass be- 

 fore it, that is, inverted. The third glass erects, or rather restores what was 

 before inverted. The fourth represents the image as it receives it from the 

 distinct-base of the third, that is, erect. 



An Inscription on the Basis of a Pillar, lately dug at Rome ; with an Interpre- 

 tation. By Dr. Fossius. N° 183, p. 172. 



This inscription was sent by that excellent philosopher and mathematician Mr. 

 Adrian Auzout, who copied it from the stone, to Mr. Justel, by whom it was 

 communicated to the Royal Society, together with the sentiments of Dr. Vossius 

 upon it. 



Observations of the Eclipse of Jupiter by the Moon, March 31, \6s6, N. S. 



N" 183, p. 175. 



Some observations have already been given of the occultation, viz. in N° 181 ; 

 and the same is farther explained and extended by these additional observations 

 of the French and other continental astronomers, published in the Journal des 

 Sqavans. 



jin Occultation of Jupiter by the Moon, An. 1686, April 10, N. S. Observed at 

 Dantzic by M. Hevelius. N° 183, p. 178. Translated from the Latin. 



Although for 56 years past I have not omitted any observation of importance, 

 I have not been able properly to take and note down more than three of Ju- 

 piter's occultations. The first of these was An. 1646, Dec. 24 in the evening ; 

 when I could only observe the end of it. The second was An. 1679, June 5 

 in the morning ; when every thing succeeded as well as possible. The third 

 was this present year 1 686, April 10 in the evening. Of this occultation, 

 among other things, the following circumstances are chiefly remarkable, viz. 



u u a 



