SUN'S HEAT ABBOT. 149 



too trying to warrant the labor of carrying the heavy apparatus up 

 the last 2,000 feet over rugged rocks and precipices. 



In these experiments a new region of the spectrum was found 

 lying beyond that which was previously recognized by Doctor Lang- 

 ley in his work at Allegheny, and I have heard him describe the 

 thrill of discovery as he roughly mapped out this new region lying 

 far down beyond the visible end of the red. 



Almost 30 years later, at the recommendation of Director Campbell, 

 of Lick Observatory, and the writer, the Smithsonian Institution 

 erected on the summit of Mount Whitney a stone and steel building 

 of three rooms, so as to enable observers who, for any reason, require 

 the. high altitude for their work to carry it on under conditions of 

 comparative comfort. 



The first to occupy the new observing station was Director Camp- 

 bell's expedition of 1909 1 to determine the quantity of water existing 

 in the atmosphere of the planet Mars. At the same time the writer 

 observed there, with special spectrobolometric apparatus, to deter- 

 mine whether measurements of the sun's heat outside the atmosphere, 

 which had been carried on at Washington and Mount Wilson, would 

 have yielded different results had they been made at a station very 

 much higher in altitude. 



The following selection from a letter of the writer shows how 

 little the second "solar constant " expedition to Mount Whitney was 

 able to compete in impressiveness with the famous one of Doctor 

 Langley : 



Mount Wilson, Calif., September U f , 1909. 



Dear Sir: I left Pasadena about. 9.30 p. ru. August 19, and took the 11.30 

 p. m. train at Los Angeles for Mojave. I slept occasionally but with great 

 fear lest I should be carried by Mojave, and at length reached there a little 

 late, at 4.30 a. m. The train for Little Lake, mostly a freight train, left at 7 

 a. m., and. after stopping all along the way to shift and unload freight cars, 

 reached Little Lake, 3£ hours late, at 6 p. m. I got supper there and started by 

 auto stage at 6.15 p. m. Having three boxes of delicate apparatus, one of which 

 I felt it necessary to carry in my arms, the ride of 50 miles from Little Lake 

 to Lone Pine was not altogether pleasant. Two automobiles started together, 

 but the one I was in stopped near Olancha, and nearly two hours of work failed 

 to start it, so that all the passengers crowded into the other. We reached 

 Lone Pine at 11.30 p. m. At 8.30 a. m. August 21, with Mr. William Skinner, of 

 Lone Pine, as guide, and with a driver and animals to carry my baggage, I 

 started for Mount Whitney. We camped at about 4 p. m. with Mr. Robinson 

 and his packers at Big Meadow; elevation about 10,500 feet. I found that 

 nearly all the material for the house had gone up to the top, and my boxes were 

 at Robinson's camp. Mr. Skinner and I left camp at 6 a. m. and arrived on 

 the summit of Mount Whitney about 11 a. m. August 22. We found Mr. Marsh 

 with four workmen. The walls of the building were done except gables and 

 partitions, and the frame of the roof was up. The masons were laying the 



1 A Shelter for Observers on Mount Whitney, by C. G. Abbot, Smithsonian Misc. Coll. 

 (Quarterly Issue), vol. 52, pt. 4, pp. 499-506. 1910. 



