XX NOTES BY THE EDITOR. 



from the disc, and appeared to be the most conspicuous corona 

 line. 



Professor Winlock also states the probable existence of an en- 

 velope surrounding the photosphere, and beneath the chromo- 

 sphere, of a thickness from 2 to 3 seconds of arc, which gives a 

 discontinuous spectrum of all the ordinary lines, bright on dark 

 fields. 



Professor Pickering, observing with an Arago polariscope, one 

 of the four employed by Prazmowski and Savart, obtained with all 

 three results pointing to a radial polarization of the corona. The 

 light covering the moon's disc he observed to be polarized 

 throughout in the same plane, and the observations showed that 

 the Arago and other polariscopes dependent on color were suffi- 

 ciently delicate to determine this plane with accuracy. 



A writer in "Cosmos," of July 30th, sums up the progress of 

 geography for 1869-1870. We give the following abstract : 



Each year the space of unknown lands on the surface of the 

 globe grows smaller; but the investigations relative to different 

 branches of geography embrace an immense field. 



The completion of the Suez Canal and the Pacific Railroad open 

 extended ways for scientific exploration. 



Africa and the regions of the North attract, at present, the prin- 

 cipal attention of geographers. In Africa, the Abyssinian war 

 has brought out many treatises upon this particular region. An 

 Italian scientific expedition at the present moment is engaged 

 there. 



A German traveller, to whom we owe interesting studies upon 

 the shores of the Red Sea, has also explored the bordering 

 regions of Nubia in the country of the Djours, where he is occu- 

 pied principally with ethnographic researches. 



Dr. Schweinfurth, after a long residence among the Africans, 

 confirms the opinions of M. de Quatrefages, that the coloration 

 of the skin cannot serve for the distinction of different races. 



In the region of the great lakes of Equatorial Africa, Living- 

 stone pursues his discoveries with a courage not abated by 

 obstacles. 



May 30, 1869, at Ujiji, he was preparing to trace a new lake 

 at the west of Tanganyika, from which flows a great river, it 

 may be one of the sources of the Nile, which thus finds itself 

 again reported more to the south. In the south-east there are 

 the travels of Erskine upon the borders of Limpopo, those of 

 Fritsch, of Mauch, which have given hopes of rich auriferous de- 



