REPORT OP COMMITTEE ON OBSERVATORIES 167 



Association Report for 1883, may interest you, and I therefore inclose 

 a couple of copies. 



My own impression is that to reap the full benefit of a mountain 

 station one should aim at a height of fully 11,000 feet, and if well 

 within the tropics an elevation of 12,500 feet might be occupied 

 throughout the year withont serious discomfort. Such an altitude 

 in either temperate zone, however, would expose the observers to 

 the most terrible weather and great hardships in the winter — e. g. , 

 the floor of the Crater of Elevation of Teneriffe (7,200 feet, latitude 

 28^°), according to the late Professor C. Piazzi Smyth, is swept by 

 violent snowstorms every winter. The experience of residents and 

 travelers in your own mountains will furnish you with abundant 

 further examples. 



My experience at Puno on L,ake Titicaca (12,500 feet), in latitude 

 1 5 50' south, proves that observations can there be carried on under 

 favorable conditions of weather and temperature at all seasons of the 

 year. Indeed, the sky, on the whole, is much clearer in the winter, 

 and therefore better suited for observations in general, although 

 there are doubtless certain solar investigations which could in that 

 latitude be better prosecuted at a season when the sun passes within 

 a few degrees of the zenith for many weeks in succession. In the 

 months of October, November, and December the weather is often 

 very fine, I was told ; but in January, February, and the early part 

 of March clouds, and even a good deal of rain, are to be expected. 



As you will know from Copernicus, my experience in the Andes 

 was confined to the neighborhood of the Mollendo-Puno route, where, 

 through the courtesy of the railway authorities, mechanical and 

 technical aid is readily procurable; but doubtless the same mechan- 

 ical facilities would be offered on the Oroya railway, which, starting 

 from Lima, in 12 south latitude, reaches a height of fully 15,600 

 feet quite near the Pacific seaboard. Unfortunately the disturbed 

 political state of the country at the time of my visit prevented me 

 from examining this railway, but from its position so near the rain- 

 less coast it is very possible that the weather conditions near the 

 upper part of the route may be fully more favorable than on the 

 Mollendo railway. 



But I should here like to draw your attention to a point affecting 

 the personal comfort and even safety of the members of an astro- 

 nomical party on their way to a high-level station. In my opinion, 

 the whole of the ascent should not be attempted on one day; the 

 party ought to devote something like a week to inuring themselves 



