POPULAR ASTRONOMY 



i43 





aitj^uuvvv 



R5PUSMl.5\5n^N6MYl 



Evening Sky Map for August. 



BY PROF. ALFRED MITCHELL, OF COLUMBIA 

 UNIVERSITY. 



The average person was disap- 

 pointed in the appearance of Halley's 

 comet in that it did not live up to the 

 reputation made for it by the daily 

 press. In reading of the tremendous 

 velocity of forty miles per second that 

 it had at one time with respect to the 

 earth, one almost naturally looked to 

 see it move in the heavens like a gigan- 

 tic sky-rocket, changing its position 

 tremendously in a few hours — and yet 

 the earth is moving continuously at 

 nearly half the above velocity. In 

 fact, most comet gazers expected to 

 see an object nearly as bright as the 

 moon with a long brilliant tail resemb- 

 ling a gigantic meteorite or shooting 

 star. Though comets fall far below 

 such expectations, they have imnortant 

 connections with meteors and shooting 

 stars; and there is no month in the 

 year quite as favorable as August for 

 a study of these interesting objects. 

 The warm nights of summer are more 

 comfortable for keeping a watch of the 

 heavens, and one can take himself out 

 into the fields and throw himself upon 

 the grass, or if not in th : country, he- 

 can take a pillow with him to the up- 

 stairs verandah or to the roof, and 

 stretched at full length, can gaze in 

 comfort at the skies. Then, in the sec- 

 ond place, there are more shooting 

 stars in the early part of August each 

 year than there are, except at rare 

 intervals, at any other time. 



Who of us is not familiar with the 

 darting rush of lisfht through the sky 

 which we call a shooting star, or in its 

 more splendid forms a meteor or fire- 

 ball. The meteor is generallv accom- 

 panied by a luminous train of light, 

 which marks out the path of the body. 



and which at times persists long after 

 the shooting star has disappeared. 

 Those paths are more or less curved, 

 seldom exactly straight, and here and 

 there along the path we can see where 

 the direction has suddenly changed. At 

 times this change in direction is accom- 

 panied by a violent explosion which at 

 times may be heard for miles. 



When these bodies reach the earth, 

 they are called meteorites or aerolites, 

 and whether found at the time or hun- 

 dreds of years later, they are highly 

 prized in our museums. When such an 

 object has been observed to fall by 

 many people it is interesting to note 

 how very unsatisfactory nearly all 

 accounts are, the appearance and the 

 noise being terribly exaggerated. 



One of the finest collections of me- 

 teorites in the world is at the Ameri- 

 can Museum of Natural History in 

 Xew York City. In addition to the 

 Ward-Coonley collection having soeci- 

 mens of over ninety per cent, of all 

 known meteorites, they have there the 

 largest known meteorite of thirty- 

 seven and a half tons, brought by 

 Peary from Greenland ; the interesting 

 Williamette meteorite, found in Ore- 

 gon in 1902, the third largest in the 

 world, and many others. Though 

 these large objects were not seen to fall 

 the scientific man has certain sure 

 tests which make it certain that these 

 bodies came from the skies. 



There seems to be no difference ex- 

 cot size between these meteorites and 

 the tiny shooting stars which we 

 Sflimpse from the corner of our eye. 

 It is rather easy to estimate the num- 

 ber of shooting stars that are seen 

 daily. If one. on a clear moonless 

 evening, should gfet away from the city 

 bVhts, it would be only a few minutes 

 before he would see a shooting star. If 



