362 



THE GUIDE TO NATURE 



PoPUL?^1?\STRqNoMY 



The Heavens in March. 



BY PROF. ALFRED MITCHELL, OF COLUM- 

 BIA UNIVERSITY. 



Seldom has the astronomical world 

 been so completely taken by surprise 

 as it was by the brilliant naked eye 

 comet that each and every one of us 

 saw. A month ago the professional 

 astronomer was beginning- to devote 

 his energies more and more to Hallev's 

 comet, for nothing else of an unusual 

 nature loomed big in the astronomical 

 horizon for the year iyio. This inter- 

 esting periodic comet discovered as it 

 was by Prof. Wolf two hundred and 

 twenty days before perihelion passage 

 has been brightening gradually, but 

 so slowly that the "man in the street" 

 had begun to lose interest in it, for it 

 was not merely a "nine days' wonder." 

 The new comet, or as it is technically 

 known. Comet A, 1910, apparently 

 caught the comet-seekers napping, and 

 as a result these guardians of the celes- 

 tial sphere have lost somewhat of their 

 excellent reputation for carefully and 

 sleeplessly patrolling the heavens, 

 looking for these stray visitors from 

 outer space which come in to disturb 

 the quiet and equanimity of our peace- 

 ful lives. Comets have always been 

 looked upon with fear and dread even 

 as far back as Homer, who in the Iliad 

 speaks of "the red star that from his 

 flaming hair strikes down diseases, 

 pestilence and war." On account of 

 their bad reputations, and their un- 

 usual appearances, astronomers have 

 been most assiduous in searching for 

 them, and it is a matter of no little 

 chagrin that the citadel has been ap- 

 proached and stormed by the enemy 

 without having been seen by the sen- 

 tries. Comet A, iqio was discovered 

 on January 17 by Innes at Johannes- 

 burg, South Africa. At the time it 

 was only 2 degrees west and 4 degrees 

 south of the sun, and it was bright 

 enough to be seen even after sunrise. 



As it was then almost at perihelion, 

 it changed its position in the heavens 

 rapidly and quickly increased in 

 brillancy and in a' few days ri- 

 valled in brightness the evening star 

 Venus. Continued cloudly weather 

 throughout the United States deterred 

 us from seeing it for nearly a week, 

 but what splendid object it "was when 

 we did see it ! Even in the city where 

 we had the dust and smoke the glare 

 of the city lights and the lack of hori- 

 zon to contend with it showed up 

 beautifully! For the benefit of ama- 

 teurs who think they possess keen eves 

 a few measurements of the length of 

 the tail are given. On Sunday, Janu- 

 ary 23, the tail was io° in length, (we 

 may remind those who have forgotten 

 it, that the distance between the "point- 

 ers" of the Dipper is about 5 ). The 

 tail increased greatly in length and by 

 the end of January had reached the 

 enormous length of 35 ° as measured 

 by Prof. Douglass of the University 

 of Arizona, over one-third the distance 

 from horizon to zenith. It quickly 

 faded after that and on February 3, 

 when it was practically invisible in 

 New York City, due to smoke and 

 lights. Prof. Barnard estimated its 

 length at 20°. The tail was then very 

 broad, widening out rapidly from the 

 head, and an excellent photograph of 

 it obtained the same night showed in 

 addition to the main tail another much 

 shorter tail or extension pointing in 

 the opposite dierction and extending 

 twelve minutes of arc towards the 

 sun. The last time this phenomenon 

 was noted in the great comet of 1882: 

 and the great comet of 1910 is the most 

 brilliant comet we have had in all that 

 time. 



It likewise is the most remarkable 

 comet in that period, judging from its 

 Spectacular appearance, the length and 

 brillancy of its tail, and its curious 

 composition, for the spectroscope 



