SCHIAPARELLl'S LATEST VIEWS REGARDING MARS. 115 



1864. Dawes detected eight or ten of the canals. 



1867. Hiiggins detected lines due to the presence of water vapor in 

 the spectrum of Mars. 



1867. Proctor determined the period of rotation of Mars within 0.1 

 second. 



1877. Hall discovered the two satellites of Mars. 



1877. Green made a very excellent series of drawings of the planet, 

 superior to anything which had preceded them. 



1877. Schiaparelli made the first extensive triangulation of the sur- 

 face of the planet, and added very largely to the number of known 

 canals. 



1879. Schiaparelli detected the gemination of Nilus, the first known 

 double canal. 



1882. Schiaparelli discovered numerous double canals, and announced 

 that the appearance formed one of the characteristic phenomena of the 

 planet. 



The most reliable confirmation of this phenomenon hitherto reported 

 has come from Perrotin, of Nice, and A. Stanley Williams, in England. 

 If Schiaparelli's theory is correct, that the duplication occurs only 

 between the spring and autumn equinoxes of the Northern Hemisphere, 

 the last opportunity to witness it was in 1890, and the next will be iu 

 January and February of 1895, unless the planet proves to be too 

 remote at that period. 



Very few of Schiaparelli's writings have ever been translated into 

 English, and none so far as I know, hitherto, without the intervention 

 of some other language, such as German or French. The following 

 translation is from Natura ed Arte for February 15, 1893. It gives 

 the latest expression of his views upon the periodical inundations expe- 

 rienced by the planet, upon the nature of the seas, the canals, and the 

 gemination of the latter. 



Lowell Oeservatory, Flagstaff, Ariz., Auguat 26, 1894. 



THE planet mars. 



By Giovanni Schiaparelli. 



Many of the first astronomers who studied Mars with the telescope 

 had noted on the outline of its disk two brilliant white spots of rounded 

 form and of variable size. In process of time it was observed that 

 while the ordinary spots upon Mars were displaced rapidly in conse- 

 quence of its daily rotation, changing in a few hours both their posi- 

 tion and their perspective^ the two white spots remained sensibly 

 motionless at their posts. It was concluded rightly from this that 



