1902.] 



LOWELL — AREOGRAPHY. 



233 



itself to be knotted with spots at its intersections. Many of the 

 spots in the bright regions were detected by Pickering in 1892. 

 Lastly, the two systems turned out to be connected together, the 



Fig. II, 



20 JO 'K) so so 70 So ?0 «» "O 



Lowell Observatory 



MAR5 I89Q-9. 



Map of Lowell, 1898-99. 



Fig. 12. 



10 20 JO «o so 00' 70 80 so 100 110 120 

 LOWELL O&SERVATORY 



• ISO I60 /TO leo 'SO 200 Z/O 220 Z30 2«0 I 



MARS 1900-1 



Map of Lowell, 1 900- 1 901. 



one system running into the other and marked by nick-like points 

 in the coast line, thus making one united mesh of lines and knots 

 superposed over the whole surface of the planet. 



