38 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



SPECTRUM OF NEPTUNE. 



Mr. H. C. Vogel, of the observatory at Bothcamp, has spec- 

 troscopically examined the light of Neptune, the most ex- 

 treme of the known members of our solar system, and found 

 the spectrum of this planet identical with that of Uranus. 

 Eight lines of absorption have been measured, and they coin- 

 cided with those of Uranus. Red could not be perceived. 

 This result differs somewhat from that of M. Secchi, who only 

 considers the spectra of the two planets as very similar. 19 

 C, xxviii., 1872, 223. 



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THE LOST COMET. 



Just one hundred years ago a new comet was discovered 

 by Montaigne. It was so faint and difficult of observation 

 that no time could be fixed for its return. In 1826 a comet was 

 found by Yon Biela, and, on computing the orbit, it proved 

 to be identical with that of 1772. Further investigation 

 showed that it was also observed in 1805, but was not then 

 recognized as the same. It was, therefore, a periodic comet, 

 and the period of its revolution was found to be six years and 

 eight months. It has since been known as Biela's comet, 

 from its discoverer of 1826. The next two returns were not 

 favorable for its observation, so that it was not again satis- 

 factorily detected till 1845. It was seen in November and 

 December of that year by a number of observers, who noticed 

 nothing unusual ; but in January it was found to have suf- 

 fered an accident such as was never before known to happen 

 to a heavenly body, and of which no explanation has ever , 

 been given. It was split in two, and for some months was ob- 

 served as two comets. In 1852 it appeared again, and now 

 the two comets were nearly two million miles apart. They 

 disappeared from view about the end of September, and have 

 never been seen since, although they must have returned in 

 1859, and again in 1866 and 1872. The return of 1866 was 

 quite favorable, but, although the most powerful telescopes 

 searched for it, all was in vain. The comet had vanished from 

 the heavens. 



The earth crossed the orbit of this comet about the end of 

 November. Professor Newton was thus led to infer that, 

 though lost to sight, the fragments of the comet would be 



