184 PROCEEDINGS OF THE AMERICAN ACADEMY 



V. That the inner portion of the dusky ring disappears in the 

 light of the planet at that part which is projected upon its 

 disk. 



VI. Tliat the planet is less luminous near its limb than in the more 

 central parts, the light diminishing gradually in approaching 

 the border. 



VII. That the dusky ring is not transparent throughout, contrary to 

 all the observations made hitherto ; and that it grows more 

 dense as it recedes from the planet ; so that, at about the 

 middle of its width, the limb of the planet ceases entirely to 

 be seen through it. 

 VIII. And, finally, that the matter composing the dusky ring is 

 agglomerated here and there into small masses, which almost 

 totally prevent the light of the planet from reaching the eye of 

 the observer. 



Cambridge, Dec. 1, 1875. 



