XIV 



HUMBOLDT S CORRECTIONS 



Page 264, line 13. 



In the condensed statement of the method by which the parallax of the 

 double stars is found by means of the velocity of light, it should be said : 

 The time which elapses between the moment in which the planetary 

 secondary star is nearest to the Earth, and that in which it is most distant 

 from it is always longer when the star passes from the point of greatest 

 proximity to that of greatest elongation, than in the converse, when it 

 returns from the point of greatest elongation to that of greatest proximity. 



Page 289, line 1. 



In the French translation of the astronomical volume of the Cosmos, 

 which, to my great gratification, M. H. Faye has again undertaken, this 

 learned astronomer has much enriched the section upon double stars. 

 I had myself neglected to make use of the important treatises of M. 

 Yvon Villarceau, which were read at the Institute in the course of the 

 year 1849. (See Connaissance des Temps pour Van 1832, pp. 3 128). 

 I quote here from the table by M. Faye, of the orbital elements of eight 

 double stars, the first four stars, which he considers to be the most 

 certainly determined : 



Elements of the Orbits of Double Stars. 



