38 



ASTRONOMICAL PHENOMENA AND PROGRESS. 



khanate, the population of which is esti- 

 mated by Dieterici at about one million in- 

 habitants. 



The Government of Great Britain has added 

 to the British possessions the Nicobar Islands. 

 In 1869 three islands of the chief group, Nang- 

 kovvri, Karmorta, and Trincutt, were occupied, 

 and all the islands placed under the commis- 

 sioner of the Andaman Islands. According to 



the reports of Austrian scholars, accompanying 

 the Novara Expedition, the Nicobar 'Islands 

 have an area of 725 square miles, and about 

 5,000 inhabitants. 



The area and population of the states, divis- 

 ions, and subdivisions of Asia, were in 1870 

 (according to Behm, GeograpJiiscTie Jdhrbuch, 

 vol. iii., Gotha, 1870) as follows, the indented 

 countries being subdivisions : 



ASTRONOMICAL PHENOMENA AND 

 PROGRESS. Temperature and Physical Con- 

 stitution of the Sun. Professor F. Zollner 

 communicated to the Royal Saxon Society in 

 June an elaborate paper in which he sums up 

 his own and others' late researches into these 

 problems as follows : The eruptive protuber- 

 ances are explained on the supposition that 

 they break forth from a layer of separation 

 dividing the space from which these hydrogen- 

 flames shoot up from the space into which 

 they empty themselves. Respecting the phys- 

 ical constitution of this layer, the further as- 

 sumption is necessary that it is in some other 

 state than gaseous. It may be either solid or 

 liquid. In consequence of the high tempera- 

 ture, the solid state is excluded, and the ex- 

 istence of an incandescent liquid is therefore 

 conjectured. Concerning the mass of hydro- 

 gen enclosed by this liquid layer two suppo- 

 sitions appear at first sight possible : 



1. The whole interior of the sun is filled 

 with glowing hydrogen a great bubble of 

 that gas surrounded by an incandescent atmos- 

 phere. 



2. The masses of hydrogen thrown out by 

 the volcanic outbursts which cause the phe- 

 nomena called protuberances are local aggre- 

 gations contained in hollow spaces formed 

 near the surface of an incandescent liquid 



mass, and then burst through their outer shell 

 where the increased pressure of the material 

 in the interior reaches a certain point. 



According to the first assumption, a state 

 of stable equilibrium will only occur when 

 the specific gravity of the liquid-dividing layer 

 is smaller than that of the gaseous layer 

 which lies immediately beneath it. As, how- 

 ever, the density of a gaseous globe, whose 

 particles obey the laws of Newton and Ma- 

 riotte, increases from the surface toward the 

 centre, the specific gravity of the layer of 

 division must necessarily be smaller than that 

 of the mean specific gravity of the sun. If 

 we assume that the highest limit of specific 

 gravity of this layer is the mean specific 

 gravity of the sun, we shall have to assume 

 that all the deeper-lying layers, and therefore 

 the still deeper-lying gaseous layers, have the 

 same temperature. But the interior of the 

 sun would consist, not of a gas, but of an in- 

 compressible liquid, which is the second sup- 

 position. 



Professor Zollner estimates the internal tem- 

 perature of the sun to be 68,400 0. at a depth 

 of only 27" under the visible surface of the 

 luminary, or at about -fa of its visible semi- 

 diameter. The probable minimum value of 

 the temperature of the chromosphere, he puts 

 at 27,700 C. Assuming the atmospheric press- 



