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THE GUIDE T< ) NATURE 



little opportunity was had to view the 

 phenomena mi a dark sky. Ai 9.30 

 P. M., a brilliant aurora was seen. 

 This pn ibably had nothing to do with 

 the comet, bul was connected with a 

 fine group of spots on the sun that 

 Professor Slocum had photographed 

 with the forty-inch telescope earlier in 

 the day. 



Vs the night wore on, no noticeable 

 effects of the tail of the comet were 

 seen. However, as the moon got 

 lower and lower toward the western 

 horizon a faint mist) -like cloud in the 

 east took on more and more definite 

 shape; and this proved to be tin 

 comet's tail, almost in the same posi- 

 tion where it had been twenty-four 

 hours previously. The astronomers 

 were puzzled. The comet should have 

 passed the sun before midnight, and it 

 the tail were straight, it should have 

 been seen in the west instead of the 

 east. 



The observers in Honolulu, Manila 

 and Australia, in the Pacific, were fav- 

 ored with clear weather, and closely 

 watched the sun to try and see the 

 comet during its transit. Absolutely 

 nothing was seen. The enigma of 

 comets was heightened rather than 

 decreased, the head of the comet was 

 too tenuous! We knew the tail to be 

 flimsy, but we had thought that the 

 "rocks" or "meteoric stones" forming 

 the head would gather together into 

 agglomerations big enough to be seen 

 projected on the sun. What is a comet 

 anvway? I 'alley's comet has ] > i vis- 

 iting us we know for more than two 

 thousand years, the head has been con- 

 tinuously losing matter to form the 

 tail which at this appearance was at 

 least twenty-five million miles in 

 length. And yet there is not enough 

 material in the head for us to have 

 seen any trace of it ! 



The night of Ala}' 19 was cloudy at 

 Yerkes. At other places, the head of 

 the comet was seen shortly after sun- 

 sel in the west exactly at its predicted 

 place. 'Towards morning faint streaks 

 of light in the east showed the tail ■-'ill 

 on the opposite side of the earth from 

 where the head had been seen. The 

 astronomers had been able to exolain 



the tail in the east on the morning of 

 the loth, but on this morning, the 20th, 

 it was hard to understand how it could 

 be, but there it was nevertheless. To 

 use an illustration of Professor Frost, 

 the comel is like a comma, the tail 

 more or less curved. I:i the morning 

 skies, we had been approaching the 

 comet approximately in the place of 

 its path about the sun and the curva- 

 ture had not been apparent to us. Hut 

 the curvature was there none the less, 

 and it was not at all surprising to see- 

 the tail in the east on the morning of 

 the 19th. We were moving through 

 space relative to the particles forming 

 the tail at the rate of 43 miles per sec- 

 .bnd. Twenty-four hours at this speed 

 means a distance of over three and a 

 half million miles — but there was the 

 tail of the comet in the east on the 

 morning of the 20th. There are sev- 

 eral ways of explaining how this is 

 possible, but none are quite adequate, 

 and we will have to rest till more com- 

 plete observations are at hand. 



Most of us had many fine views of 

 the comet in the evening skies before 

 the twelfth of June, when the moon 

 put an end to all naked eye observa- 

 tions. People who lived in the coun- 

 try, away from the dust and smoke of 

 the city and the glare of electric lights, 

 had a much better chance to see the 

 tail. It was so faint that the feeble 

 extensions were lost to the city obser- 

 ver. There were quite marked changes 

 in the comet's appearance from night 

 to night. On the evening of June 6, 

 Professor P>arnard obtained an exquis- 

 ite photograph with his ten-inch Bruce 

 camera. This showed practically the 

 only real activity in the tail during its 

 photographic history. A large portion 

 of matter is there seen ejected from the 

 head. The effect of this outburst was 

 seen the next evening for the comet 

 was very much fainter. 



The spectroscopic work on the 

 comet gained little of interest. During 

 the evening anpearancc. the cyanogen 

 band in the violet part of the soectrum 

 remained relatively strong in the head 

 of the comet, but it was absent from 

 the tail. As the ordinary photographic 

 plate is most sensitive to violet light, 



