398 THE POPULAR SCIENCE MONTHLY. 



of a gigantic helmet fronting eastward, to a height of 14,887 feet. 

 Mount Whitney is thus entitled to rank as the Mont Blanc of its 

 own continent. In order to reach it, a railway journey of 3,400 miles, 

 from Pittsburg to San Francisco, and from San Francisco to Caliente, 

 was a brief and easy preliminary. The real difficulty began with a 

 march of 120 miles across the arid and glaring Inyo Desert, the ther- 

 mometer standing at 110° in the shade (if shade there were to be 

 found). Toward the end of July, 1881, the party reached the settle- 

 ment of Lone Pine at the foot of the Sierras, where a camp of low-level 

 observations was pitched (at a height, it is true, of close upon 4,000 

 feet), and the needful instruments were unpacked and adjusted. Close 

 overhead, as it appeared, but in reality sixteen miles distant, towered 

 the gaunt and rifted and seemingly inaccessible pinnacle which was the 

 ultimate goal of their long journey. The illusion of nearness pro- 

 duced by the extraordinary transparency of the air was dispelled when, 

 on examination with a telescope, what had worn the aspect of patches 

 of moss, proved to be extensive forests. 



The ascent of such a mountain with a train of mules, bearing a deli- 

 cate and precious freight of scientific apparatus, was a perhaps unex- 

 ampled enterprise. It was, however, accomplished without the occur- 

 rence, though at the frequent and imminent risk, of disaster, after a 

 toilsome climb of seven or eight days through an unexplored and, to 

 less resolute adventurers, impassable waste of rocks, gullies, and preci- 

 pices. Finally a site was chosen for the upper station on a swampy 

 ledge, 13,000 feet above the sea ; and there, notwithstanding extreme 

 discomforts from bitter cold, fierce sunshine, high winds, and, worst 

 of all, " mountain-sickness," with its intolerable attendant debility, 

 observations were determinedly carried on, in combination with those 

 at Lone Pine, and others daily made on the highest crest of the mount- 

 ain, until September 11th. They were well worth the cost. By their 

 means a real extension was given to knowledge, and a satisfactory 

 definiteness introduced into subjects previously involved in very wide 

 uncertainty. 



Contrary to the received opinion, it now appeared that the weight 

 of atmospheric absorption falls upon the upper or blue end of the 

 spectrum, and that the obstacles to the transmission of light-waves 

 through the air diminish as their length increases, and their refran- 

 gibility consequently diminishes. A yellow tinge Is thus imparted 

 to the solar rays by the imperfectly transparent medium through 

 which we see them. And, since the sun possesses an atmosphere of 

 its own, exercising an unequal or " selective " absorption of the same 

 character, it follows that, if both these dusky-red veils were with- 

 drawn, the true color of the photosphere would show as a very dis- 



an inch thick, constituting metallic antennce sensitive to the chill even of the fine dark 

 lines in the solar spectrum, or to changes of temperature estimated at Tiiu^oiro of a de- 

 gree centigrade. 



