May 29, 1885.] 



SCIENCE 



447 



harness, and by them those of men, women, and little 

 children, dead of thirst; and some relics of the tragedy 

 remained at the time of our journey. I cite this as 

 an indirect evidence of the phenomenal dryness of 

 the region, — a dryness which so far served our ob- 

 ject, which was, in part, to get rid, as much as possible, 

 of that water-vapor which is so well known to be a 

 powerful absorber of the solar heat. 



Every thing has an end ; and so had that journey, 

 which finally brought us to the goal of our long travel 

 at the foot of the highest peak of the Sierras, Mount 

 Whitney, which rose above us in tremendous preci- 

 pices that looked hopelessly insurmountable and 

 wonderfully near. The whole savage mountain 

 region, in its slow rises from the west, and its descent 

 to the desert plains in the east, is more like the chain 

 called the Apennines, in the moon, than any thing I 

 know on the earth. The summits are jagged peaks, 

 like Alpine ' needles,' looking in the thin air so delu- 

 sively near, that, coming on such a scene unprepared, 

 one would almost say they were large gray stones a 

 few fields off, with an occasional little white patch on 

 the top that might be a handkerchief or a sheet of 

 paper dropped there. But the telescope showed that 

 the seeming stones were of the height of many Snow- 

 dons piled on one another, and the white patches 

 occasional snow-fields, looking how invitingly cool 

 from the torrid heat of the desert, where we were en- 

 camped by a little rivulet that ran down from some 

 unseen ice-lake in that upper air. Here we pitched 

 our tents, and fell to work (for you remember we 

 must have two stations, a low and a high one, to com- 

 pare the results) ; and here we labored three weeks in 

 almost intolerable heat, the instruments having to be 

 constantly swept clear of the red desert dust which 

 the hot wind brought. Close by these tents, a ther- 

 mometer covered by a single sheet of glass, and 

 surrounded by wool, rose to 237° in the sun; and 

 sometimes in the tent, which was darkened for the 

 study of separate rays, the heat was absolutely be- 

 yond human endurance. Finally, our apparatus was 

 taken apart, and packed in small pieces on the backs of 

 mules, who were to carry it by a ten-days' journey 

 through the mountains to the other side of the rocky 

 wall, which, though only ten or twelve miles distant, 

 arose miles above our heads; and, leaving these mule- 

 trains to go with the escort by this longer route, I 

 started with a guide by a nearer way to those white 

 gleams in the upper skies that had daily tantalized 

 us below in the desert with suggestions of delicious, 

 unattainable cold. That desert sun had tanned our 

 faces to a leather-like brown, and the change to the 

 cooler air as we ascended was at first delightful. At 

 an altitude of five thousand feet we came to a 

 wretched band of nearly naked savages, crouched 

 around their camp-fire, and at six thousand found 

 the first scattered trees; and here the feeble sugges- 

 tion of a path stopped, and we descended a ravine to 

 the bed of a mountain stream, up which we forced 

 our way, cutting through the fallen trees with an axe, 

 fighting for every foot of advance, and finally passing 

 what seemed impassable. It was interesting to spec- 

 ulate as to the fate of our siderostat mirrors and other 



precious freight, now somewhere on a similar road, 

 but quite useless. We were committed now, and had 

 to make the best of it; and, besides, I had begun to 

 have my attention directed to a more personal sub- 

 ject. This was, that the colder it grew, the more the 

 sun burnt the skin — quite literally burnt, I may say; 

 so that by the end of the third day my face and hands, 

 case-hardened, as I thought, in the desert, began to 

 look as if they had been seared with red-hot irons, 

 here in the cold, where the thermometer had fallen to 

 freezing at night; and still, as we ascended, the para- 

 doxical effect increased. The colder it grew about us, 

 the hotter the sun blazed above. We have all heard, 

 probably, of this curious effect of burning in the midst 

 of cold, and some of us may have experienced it in 

 the Alps, where it may be aided by reflection from 

 the snow, which we did not have about us at any 

 time except in scattered patches; but here, by the end 

 of the fourth day, my face was scarcely recognizable, 

 and it almost seemed as though sunbeams up here 

 were different things, and contained something which 

 the air filters out before they reach us in our custom- 

 ary abodes. Kadiation here is increased by the ab- 

 sence of water-vapor, too; and, on the whole, this 

 intimate personal experience fell in almost too well 

 with our anticipations that the air is an even more 

 elaborate trap to catch the sunbeams than had been 

 surmised, and that this effect of selective absorption 

 and radiation was intimately connected with that 

 change of the primal energies and primal color of 

 the sun which we had climbed towards it to study. 



On the fourth day, after break-neck ascents and 

 descents, we finally ascended by a ravine down which 

 leaped a cataract, till, at nightfall, we reached our 

 upper camp, which was pitched by a little lake, one 

 of the sources of the waterfall, at a height of about 

 twelve thousand feet, but where we seemed in the 

 bottom of a valley, nearly surrounded as we were by 

 an amphitheatre of rocky walls which rose perpen- 

 dicularly to the height of Gibraltar from the sea, and 

 cut off all view of the desert below, or even of the 

 peak above us. The air was wonderfully clear; so 

 that the sun set in a yellow rather than an orange 

 sky, which was reflected in the little ice-rimmed lakes, 

 and from occasional snow-fields on the distant waste 

 of lonely mountain summits on the west. 



The mule-train, sent off before by another route, 

 had not arrived when we got to the mountain camp, 

 and we realized that we were far from the appliances 

 of civilization by our inability to learn about our 

 chief apparatus; for here, without post or telegraph, 

 we were as completely cut off from all knowledge of 

 what might be going on with it in the next mountain 

 ravine as a ship at sea is of the fate of a vessel that 

 sailed before from the same port. During the en- 

 forced idleness, we ascended the peak nearly three 

 thousand feet above us, with our lighter apparatus, 

 leaving the question of the ultimate use of the heavy 

 ones to be settled later. There seemed little prospect 

 of carrying it up, as we climbed where the granite 

 walls had been split by the earthquakes, letting a 

 stream of great rocks, like a stone river, flow down 

 through the interstices by which we ascended; and. 



