MOUNTAIN OBSERVATORIES IN AMERICA AND EUROPE. 37 



feet in 1892. A hut was built here and a bridle-patli led to it and a 

 number of visitors went as high as this, riding on mules. It some- 

 times happened that a ^dsitor would arrive perfectly well, and fifteen 

 minutes later be completely prostrated. Recovery was sometimes 

 rapid, but usually not so : 



We found that all persons with blood of the white races in tlieir veins were 

 subject to the complaint, the pure-blooded Indians only being more or less exempt. 

 Half-breeds who had spent all their lives in Arequipa were often more susceptible 

 to it than ourselves. In my own case this susceptibility rapidly wore off and 

 :ifter my first night on tlie Misti I never again felt any very serious incon- 

 venience. 



Professor Pickering went to a height of 19,000 feet on Chachani 

 w'itliout any premonitions of mountain-sickness. 



The summit of this high mountain, Chachani, is said to have been 

 i-oached by several persons, but there is no authentic record of such 

 ascent until May, 1893, when Professor Schaeberle, of the Lick 

 Observatory, in company with Professor Bailey, Mr. Duncker, and 

 three natives, attempted the ascent. Professor Schaeberle and one 

 native reached Little Chachani, a peak two or three thousand feet 

 below the principal summit, the others being prostrated with mountain- 

 sickness. From his report on the solar eclipse of April, 1898, the 

 following notes are taken : 



At the first camp (about 16,000 feet in elevation) the sky was not deep blue but 

 hazy. A four- inch telescope was used at night on bright stars and the moon. 

 " While the character of the images was less favorable than at Arequipa, the 

 curious feature of very active commotion in the stellar image without any accom- 

 panying blurring, and the diffraction-rings, appeared much the same as at the 

 observatory below. The moon's image also had the same woolly, surface-creeping 

 look.'' 



Professor Schaeberle's remarks on mountain-sickness are very in- 

 structive. One member of the party (Mr. Duncker) was seriously 

 affected and became delirious. He reached a height of about 16,800 

 feet. On the next day Professor Bailey was obliged to give up the 

 ascent at about the same elevation. The Indian guides were not in 

 the least affected, either by cold or mountain-sickness ; they ate freely 

 and carried considerable loads. Professor Schaeberle's full and inter- 

 esting report {oj). cit) should be read. He is of the opinion that it 

 will always be impossible for observers to live and work at these great 

 altitudes. 



The main interest to astronomers in the Harvard College Observatory 

 ex])editions to South America is in the establishment of a well- 

 equij)ped observatory at Arequipa (8060 feet). Here a large equa- 

 torial of thirteen inches aperture was installed in 1891, and it has been 



