J. A. C. OUDEMANS. 
„„but iiiterniptioiis t'roni cloiul. Satellite I traiisitted ou the S. Ecjua- 
„„tovial bclt, (N. coinpoiient). fviiufduileli/ on its enteriiig the dise it 
„„becanie lost to vicw. At 1 1'^ 19'" a minute dark spot was seen about 
„„in the position which the Satellite shoidd have thon occupied. The 
„„shadows of Satellites I and II were confonnded together at this tiine^ 
„„thei'e seeming to be one very large, slightly oval, black spot. At 
„,/Ll''5î)"' the two shadows were seen nearly se])arated, tluis, ^* 
„„The preceeding shadow must be that of 11, the followiug and viuch 
„„smaUer one that of I. At 1£''10'" satellite I was certainly visible as 
„„a dark spot, niuch smaller than the shadow of either Satellite. It had 
„„raoved with respect to the shoulder of the Red Spot Hollow, so that 
„„there could be no doubt of its ideutity. It is ou the north band of 
„„the north (south) equatorial belt. (£). Satellite 1 [This should evi- 
„„dently be II] shines briglitly on the dise near the limb. Deliuition 
„„good, but much tliin cloud about.'"' 
,/rhe foregoing is au alniost literal transcript from luy observation 
„Book. 1 take it that wheu Satellite 1 entered on the dise of Jupiter, 
„it was already partly eclipsed by the shadow of 11, so that it becanie 
„lost to view iiumediately , instead of shining, as usual, for some tinie 
,,as a brillaut dise. Also that the minute dark spot seeu at ll''4'y'" was 
„produced by the portion of the shadow of 11, then projected on 1. 
„Also that the small size of the followiug shadow spot at 11''5!)'" was 
,,due to a part oïdy of the sliadow of [[ being projected on the dise 
„of Jupiter, other part of this shadow haviug been intercepted by Satel- 
„litel. (3). 
— - — — „But combining Mr. Comas' observation with iny owu, 
„there eau be no doubt but that Satellite 1 was actually partially eclip- 
„sed by the shadow of II ou the night of August 14, 1891 . So far as 
„I am aware, this is the only indubitable instance of one Satellite being 
„eclipsed by the shadow of another" 
„P.S. The above times are Greenwich meau times. The Nautical 
„Almauac tirae for the trausit ingress of Satellite I is If^S^""''. (4). 
Avant de passer au calcul des instants de pareilles conjonctions hélio- 
centriques, nous avons examiné jusqu'à quel point en général des 
éclipses d'un Satellite par l'ombre d'un autre sont possibles. Que de 
pareilles éclipses sont réellement possibles, cela nous est prouvé par 
les ombres des Satellites sur Jupiter même. Mais la question était de 
