i8 



THE GUIDE TO NATURE. 



P6PULW^STRDN5MY 



The Heavens in May. 



BY PROF. ALFRED Ml'i'CHELL, OF COLUM- 

 BIA UNIVERSITY. 



The crucial days in the history of 

 Halley's Comet are now at hand, and 

 each day during the first half of May 

 will bring it closer and closer to the 

 earth, and make it brighter and brighter 

 to our eyes. We wonder whether it is 

 going to disappoint us, and be a less 

 brilliant object than we had hoped. So 

 much has been written about Halley's 

 Comet, its interesting history, its verifi- 

 cation of prediction, its close approach 

 to the earth in the month of May, the 

 comet passing across the face of the sun 

 and the earth sweeping through the tail, 

 that even those never before interested 

 in astronomy have been keyed up to 

 expect a grand and glorious sight. Is it 

 going to live up to its reputation? Or is 

 it to present a public appearance without 

 a magnificent tail? At the present writ- 

 ing (April 15), it is impossible to say 

 with certainty what will happen a month 

 hence, but the present prospect is not 

 alluring. As the readers well know, the 

 comet passed on the far side of the sun 

 on March 26. and then moved into the 

 morning sky. On April 8 the comet was 

 far enough from the direct rays of the 

 sun to be seen. On the morning of April 

 12, at 4:30, Professor Barnard saw the 

 comet on a dawn-lit sky, rather faintly 

 in the 5-inch guiding telescope of the 

 Bruce camera, and it then did not show 

 a trace of tail ; and this, too, but eight 

 days from perihelion when the comet's 

 tail itself is brightest. It is altogether 

 likely that the comet was to have been 

 visible to the naked eye, if it has been 

 projected on a dark sky — but we must 

 confess that we are disappointed in its 

 feeble showing. Still the comet will in- 

 crease forty fold in brightness by the time 

 it first comes into the evening sky, and 

 no doubt it will then be a fine object. 

 However, even though it may be fainter 

 than we had expected, it should readily 



be visible to the naked eye on any morn- 

 ing during May up to and including the 

 sixteenth. To find the comet during this 

 time, get up about an hour and a half 

 before sunrise and look a little north of 

 east towards where the sun is to rise. 

 As has been pointed out repeatedly, 

 the comet is to transit the face of the 

 sun during the night of May 18. The 

 exact time that this will take place is a 

 little uncertain, but the latest calculations 

 seem to show that the comet will be 4 or 

 5 sees, north of the centre of the sun's 

 disk about 11 :20 P. M. Eastern Standard 

 time. The comet will encroach on the 

 western limit of the sun half an hour 

 earlier, and the total time of transit will 

 be almost an hour. According to these 

 figures, the sun will have set not only 

 in the Eastern part of the United States, 

 but on the Pacific slope as well. One 

 would need to go to the islands of the 

 Pacific to observe the phenomenon. And 

 what would we see if there? The head 

 of the comet according to measures of 

 Professor Barnard is over 200,000 miles 

 in width. This, only fourteen million 

 miles away projected on the sun six 

 times farther off would be sufficient to 

 cover up the whole sun. But the head 

 of the comet as a whole is so rare that 

 it would probably obstruct so little light, 

 that it will be impossible to detect any 

 change in the sun's appearance. 



ECLIPSE DURING MAY. 



The eclipse of the Sun, which takes 

 place on a lay 9, begins about 3:30 

 A. M., Eastern Standard time, will not 

 be visible anywhere in the western 

 hemisphere. 



But if this eclipse is invisible to us, 

 another on the night of May 23 and 

 morning of May 24 will be visible 

 throughout the United States and 

 Canada. This will be an eclipse of the 

 moon, which will begin and end as fol- 

 lows, the times being given in Eastern 

 Standard Time : 



