846 PERCIVAL LOWELL. 



through this country. On their return to Korea he remained for 

 some time as the guest of the government. The result of this experi- 

 ence was a vohime entitled " Choson — The Land of the Morning 

 Calm." The work is full of imagination and charm and infused with 

 the light touch and true literary gift which never deserted him, and 

 was as carefully fostered in his scientific work as elsewhere. His 

 writings during this decade include the "Soul of the Far East," which 

 Janet, the French psychologist, has cited as showing a remarkable 

 insight into the Oriental mind; also a treatise on some hitherto little 

 known aspects of Shintoism; and "Xoto," a delightful account of 

 his travels in an out-of-the-way corner of Japan. 



He had always taken a keen interest in Schiaparelli's work on Mars. 

 In the early nineties that distinguished astronomer's eyesight had so 

 far failed that it was e^^dent his observing days were over. Then 

 Lowell determined to take up Schiaparelli's work where the latter 

 had left it. 



Before establishing an observatory, with characteristic thorough- 

 ness, he searched diligently for the best available spot — his investi- 

 gations including sites in America, France, Algiers, the Mexican 

 Plateau, and a station in the Andes. 



One of the results of these investigations was to show that the 

 "seeing" on an elevated plateau is much better than on a mountain 

 top. While no place has been found better than the site chosen at 

 Flagstaff, Arizona, it seems probable that even better results would 

 have been obtained could the Observatory have been set back a mile 

 or two from the edge of the table land on wliich it stands. 



The Observatory founded in L894 was intended chiefly for a study 

 of the planets, especially Mars. But the investigations at the Obser- 

 vatory have been by no means confined to this field, much valuable 

 work having been done on the constitution of comets, and the spectra 

 and velocities of nebulae; while many refinements in stellar photog- 

 raphy have been perfected there. Here the rotation of Venus and 

 Uramus were both determined by the Doppler effect. Two of Lowell's 

 mathematical investigations are of special interest. His "Memoir 

 on a Trans-Xeptunian Planet" gives the results of many years of 

 painstaking labor, by himself and a staff of computors. The. analysis 

 of the disturbances produced on the outer planets by this unknown 

 body was conducted by methods of celestial mechanics, differing 

 considerably from those employed by Adams or Leverrier. It has 

 not as yet been possible to verify the results either visually or photo- 

 graphically. A "Memoir on Saturn's Rings" is a most ingenious 



