268 FRAGMENTS OF SCIENCE. 



storm, wore a very wild appearance. Round the horizon it 

 was of steely brilliancy, while reddish cumuli and cirri 

 floated southward. When the sky was quenched behind 

 them these floating masses seemed like dull embers sud- 

 denly blown upon ; they brightened like a fire. In the 

 Alps we have the most magnificent examples of crimson 

 clouds and snows, so that the effects just referred to may 

 be here studied under the best possible conditions. On 

 August 23, 1869, the evening Alpenglow was very fine, 

 though it did not reach its maximum depth and splendor. 

 Toward sunset I walked up the slopes to obtain a better 

 view of the Weisshorn. The side of the peak seen from the 

 Bel Alp, being turned from the sun, was tinted mauve ; 

 but I wished to see one of the rose-colored buttresses of the 

 mountain. Such was visible from a point a few hundred 

 feet above the hotel. The Matterhorn also, though for the 

 most part in shade, had a crimson projection, while a deep 

 ruddy red lingered along its western shoulder. Four dis- 

 tinct peaks and buttresses of the Dom, in addition to its 

 dominant head all covered with pure snow were red- 

 dened by the light of sunset. The shoulder of the Alphu- 

 bel was similarly colored, while the great mass of the Flet- 

 schorn was all a-glow, and so was the snowy spine of the 

 Monte Leone. 



Looking at the Weisshorn through the Nicol, the glow 

 of its protuberance was strong or weak according to the 

 position of the prism. The summit also underwent a 

 change. In one position of the prism it exhibited a pale 

 white against a dark background ; in the rectangular posi- 

 tion, it was a dark mauve against a light background. The 

 red of the Matterhorn changed in a similar manner ; but 

 the whole mountain also passed through striking changes 

 of definition. The air at the time was filled with a silvery 

 haze, in which the Matterhorn almost disappeared. This 

 could be wholly quenched by the Nicol, and then the 



