Marvels of the Universe 



25 



o 



This light is visible, not onl_v in the immediate vicinity of tlie poles, but sometimes as far as forty 

 or fifty degrees away from them. For instance, the Magnetic North Pole is situated at a latitude 

 of 78° north, and at a longitude of 71° west of Greenwich (1900). Thus the limit of the Northern 

 Lights zone in the East (Asia) is almost at the 40th parallel, while on the other hand, in the West 

 (America) it extends nearly to the 20th. 



At a latitude not too far north — for instance, Scandinavia — the Aurora Borealis is generalh' 

 green, but sometimes also violet and red. The violet colour always appears at the extreme edge, 

 or underneath the light wave. The variations in the colour are probably due to the breaking-up of 

 the rays in the aqueous vapour, and probably the nature of the air also contributes, for the sun also 

 has different colours at different times, and the Northern Lights seen in daylight in spring are rosy 

 red, but gradually change to green as the twilight comes on. 



It is a popular sa^'ing that hard frost follows a vivid display of the Northern Lights. This is 

 not correct, for during the last fifteen years I have observed about four hundred such displays, 

 and have come to the conclusion 

 that, in ninety- cases out of one 

 hundred, warmer weather follows 

 almost immediatel}-. On the other 

 hand, it is correct to say that bad 

 weather often follows the Northern 

 Lights, and this is easily explained. 

 As the light waves can form clouds. 

 it is quite natural that cloudy weather 

 results. In winter this generally 

 makes the air milder, and the change 

 of temperature causes wind. Thus 

 we have the bad weather. 



The Aurora Borealis is not affecte<l 

 by moonlight or clouds. It can some- 

 times be seen in summer, but only in 

 the twilight zone between latitudes 

 58 and 54. It is most vivid in 

 October and March, or when sun- 

 spots are in process of formation. 



When one has first discovered the 

 most active side of the sun, one may 

 be fairly sure that vivid Northern 

 Lights will appear after the lapse of 

 twenty-seven days, when the sun 

 turns the same side to the earth. 



And now some particulars of the 

 circumstances under which my draw- 

 ings were made. I have always been 

 interested in the Northern Lights, 

 and wished to possess some pictures 

 of them, but as these are scarcely 

 to be found outside scientific works, 

 there was nothing else for me to do 

 than to set to work myself. First 

 I tried photography. Our cameras 



nil j'eniiisxuin '>J j I'i'/tc Jioijill ,S:>ri, n> . 



SOUTHERN LIGHTS. 



This photo and its companion, both taken in the Antarctic Regions, 

 fittingly Ecco.-npany the drawings of M. Raebel, as they demonstrate the 

 essential similarity of the Northern and Southern Lights. 



