■/-<"■■ >i pliol.-giaph 



Figure 124. 



Hallt-y's Cornel, May 4lh, 1910. In the dark night and clear air of New Zealand, the end of the tail 

 seemed fully twice as wide as in this photograph. 



THE NEW ASTRONOMY. 



COMETS. 

 Bv PROFESSOR k. W. BICRERTON. 



Thkik Occ.vsioNAi. .Ma(.xii-ki;nce. 

 \\'hi:.\ one has seen Comets at tlieir greatest mag- 

 nificence, there is no cause to wonder that during 

 the long ages of ignorance these celestial visitants 

 shoukl have l>een looked upon with awe and fear. 

 Sometimes they seemed 

 to be fiery chariots to 

 carry the soul of the 

 dead hero to eternal 

 glory, or as portents 

 of disaster to tell men 

 to repent and to change 

 their evil wavs. 



When a youth, I saw 

 Donati's Comet as a 

 vast luminous scimitar 

 stretching from zenith 

 to horizon, its vast 

 dimensions d w a r fi n g 

 everything. I remember 

 how toy-like the trees 

 and houses looked in 

 contrast with the vast 

 immensity of this superb 



FiGl.'KE 1 



Diagram illustrating the path of the Comet. The dotted 



line represents the orbit of a comet. The diagram shows 



the radial direction of the tail from the sun, the retardation 



of its distant part into a curve. 



the Antipodes. Halley's Comet was still bigger than 

 Donati's. .\t its best it subtended an angle of fully 

 one hundred and ten degrees. In the early morning, 

 as it rose, tail first, it had the appearance of a broad 

 sil\er\- aurora springing up and covering a great 

 w idth of the Eastern 

 horizon. Gradually as 

 it rose it narrowed and 

 increased in intensit}-. 

 It was many hours 

 before the head came 

 into sight and the 

 whole majestic spec- 

 tacle revealed itself. 

 (See Figure 125.) When 

 full}- in sight the dawn 

 took something from 

 its brilliancy, but even 

 when thus diminished it 

 was a memorable sight. 

 Strange that its appear- 

 ance should have been 

 so insignificant in Eng- 

 land. This may have 



comet. Then again, the same effect repeated itself w ith been partl\- due to the haze in the air. When one is first 

 the recent visit of Hallev's Comet ; only as I saw it in in New Zealand, the extreme clearness of the atmos- 



