294 



M. F. Zollner on the Temperature and 



It can now be easily shown that in the present case, to a very 

 close approximation, the ratio of the quantities of gas particles 

 which at the lower and upper limits of the chromosphere lie in our 

 line of vision agrees with the ratio of the densities in the chromo- 

 sphere at the same limits. 



Let g 1 g l and g^g 2 in the annexed figure denote the two visual 

 lines which pass through the chromosphere at its lower and 

 upper limits. The radius r of the sun's disk is drawn about 96 

 millims. long ; so that, assuming a mean apparent semidiameter 

 of the sun of 16' or 960", 1 millim. in the figure corresponds to 

 an apparent magnitude of 10" on the sun's disk. If, then, the 

 mean altitude of the chromosphere be taken at from 10" to 15", 

 it will be represented by the distance between the lines g 1 g 1 and 

 g 2 g<2 m the figure. 



