REPORT OF COMMITTEE ON OBSERVATORIES 95 



During my stay in the San Gabriel mountains I watched the dust 

 line closely. It often rose higher than I was accustomed to see it 

 near the coast in central California. It became evident that an 

 observ'atory at an elevation of less than 4,000 feet would often be 

 below it, but that it does not usually rise much higher than this. 

 Exceptions, however, do occur. At times it rises to 6,000 feet or 

 more. These appear to correspond to the times when great volumes 

 of air are moving from the desert to the sea, volumes so great that 

 they cannot be passed through the dip in the range at Cajon canyon, 

 and must perforce go over the mountains. This happened once 

 during my stay at Mount Wilson. After some hot days in the val- 

 ley a strong wind came over the mountain from the north, and the 

 dust line, which before had been high, now rose above the peaks in 

 the immediate vicinity. This lasted for a few days, and then the 

 dust cleared from the valley, and the houses in it were again easily 

 in view. Never a day passed while I was there that Grayback and 

 San Gorgonio, the highest peaks in the San Bernardino range, were 

 not visible. Again I could see without difficulty the lower moun- 

 tains to the .southeast — Palomar, the three Cuyamaca peaks, and 

 their lower neighbors, some of them fully 120 miles away. Views 

 such as this are not exceptional. There are some days when the 

 dust rises high and thick, but according to the most reliable infor- 

 mation, this does not happen many times in the year, and it certainly 

 did not happen during my sta5^ 



The summit of Mount Wilson is situated in the southwest quarter 

 of .section 29, T. 2 N., R. 11 W., San Bernardino base line and 

 meridian. This section is at present owned by the Pasadena and 

 Mount Wilson Toll Road Company', of which corporation Mr. Wm. 

 R. Staats and Mr. J. H. Holmes, both of Pasadena, at present hold 

 a majority of the stock. This company also owns the west half of 

 the southeast quarter of section 30, and the west half of the north- 

 west quarter of section 32, these being the sections which join sec- 

 tion 29 on the west and south respectively. This company also 

 owns the toll trail from the foot of Eaton canyon to the summit. 

 All other lands in the immediate vicinity of the summit are owned 

 and controlled by the United States Government, and form part of 

 the San Gabriel Forest Reserve. Messrs. Staats and Holmes, Pro- 

 fessors Campbell and Hale of your Committee, and Mr. T. P. 

 lyUkens vi-sited Mount Wilson while I was there, and during their 

 stay a number of questions which would arise in practical form if it 

 were decided to place an obser\'atory on Mount Wilson were dis- 



