NATURE FOB ITS OWN SAKE 



Light seen 

 through 

 clear air. 



Light teen 

 from, moun- 

 tain tops. 



porarily make the sky and distant hills look 

 bluer, the sun whiter, the light purer. Cold 

 that is intense enough to rid the air of moisture 

 will also make a noticeable difference in the 

 quality of the light. In Manitoba, where the 

 thermometer often sinks many degrees below 

 zero, a bright winter day reveals an air the moist- 

 ure of which is frozen into floating crystals of 

 hoar-frost, the sky appears cobalt-blue, the sun 

 is white, and when it rises in the morning it is 

 accompanied by two sun-dogs or parhelia, one 

 on each side, and almost as brilliant as the sun 

 itself. The result is a bewildering display of 

 white light that borders upon blue. Every 

 snow crystal glitters, the cup of the sky seems 

 to be lifted into infinite space, the snow shad- 

 ows are intensely blue, and the running waters 

 are dark-purple in hue. 



As we rise above the denser strata of at- 

 mosphere that lie along the earth, by ascend- 

 ing mountain heights or otherwise, the light 

 changes even more positively. From the top 

 of Mt. Blanc the stars are seen at midday shin- 

 ing upon a dark blue-violet field that extends 

 down to the horizon ; from Pike's Peak the sky 

 is seen to be of a violet hue at times, and not in- 

 frequently blue-black ; and from Mt. Whitney 



