before or after new moon. This illumination is not much 

 greater than that observed in some total eclipses, but it 

 seems difficult to suppose that the light of the narrow ring 

 or thread of sun-light round the earth's disk as seen from 

 the moon, and greatly subdued as it must undoubtedly 

 be by passing through the earth's atmosphere, could be 

 comparable with the light from an almost fully illuminated 

 hemisphere of the earth, and it therefore became necessary 

 to inquire whether any other source existed which would 

 contribute light sufficient to render the moon so distinctly 

 visible as it sometimes appeared during total eclipses. 



At the time of maximum phase during the late eclipse, 

 or when the centre of the moon was nearest to the central 

 line of the earth's shadow, the apparent diameter of the 

 earth as seen from the moon would be 1°2G'41" greater than 

 that of the sun, and therefore, besides the whole of the 

 disk of the sun, the whole of the lower corona, or corona 

 proper, would be covered by the earth, but according to the 

 statements of observers of total solar eclipses the outer 

 corona extends to a much greater distance on each side of 

 the sun. than the semidiameter of the earth as seen from 

 the moon, and from the estimations of the brightness of 

 this uncovered portion by some observers, it seems probable 

 that to it may be due a not inconsiderable portion of the 

 light which renders the moon visible when immersed in the 

 earth's shadow; and this probability is increased when it is 

 considered that the intensity of the light of the corona, as 

 seen from the earth, is much reduced by the absoption of 

 the atmosphere, an effect which would not be produced in 

 the case of the moon. 



"On the Diamond-bearing Rocks of South Africa," by 

 Professor H. E. RoscoE, LL.D., F.KS., &c. 



The communication opens with an account of the general 

 features of the diamond-bearing region based chieflj" on the 



