24 



HISTORY OF ASTRONOMICAL DISCOVERY. 



which the Copernican system as then developed might well have justified when viewed as 

 a whole, we are not warranted in interpreting his rejection of it much to his disparage 

 ment. 



The career of Tycho is far more satisfactory as a practical astronomer than as a 



theorist ; indeed, few men have done so 

 much for the advance of the science, or are 

 more worthy of praise for the amount of toil 

 they have undergone, and the success of 

 their labours. In the year 1572, the re 

 markable event of a stellar apparition at 

 tracted the attention of Europe, and excited 

 universal astonishment and speculation. It 

 was early in November, when Tycho, who 

 then resided at his paternal home, observed 

 a star of great splendour in the constella 

 tion Cassiopeia, which he had never seen 

 before, as he was walking across the fields 

 about ten o'clock in the evening. It beamed 

 with a lustre quite unwonted in that part of 

 the heavens. It could not have escaped his 

 observation had it previously been there. 

 He suspected at first an optical illusion oc 

 casioned by some defect of his own vision, 

 but found a group of peasants gazing upon 

 it with as much astonishment as himself. Its 

 place he at once fixed by his instruments, 

 and noted the fact with all its circumstances 

 in his journal. Soon afterwards, when at 



Copenhagen, he found that the scientific men of the university had not observed the 

 stranger, and excited some derision at a convivial party by mentioning the phenomenon, 

 which, however, he soon turned into surprise by pointing out the star. One of his works 

 is devoted to this object. The same star was observed by Cornelius Gemma, who had par 

 ticularly examined that part of the heavens two nights previous, and was confident of its 

 not being present then. It continued visible for the space of sixteen months, gradually 

 diminishing in lustre, until it finally vanished in March 1574. The brilliance of this 

 star was so great as at first to cause Tycho's staff to deflect a shadow. Its light changed 

 from white when the brightest to a yellowish hue, and afterwards had a fiery tinge like 

 Mars, becoming livid like Saturn before its disappearance. During the whole time of its 

 visibility, its place in the heavens remained unaltered ; it had no annual parallax, conse 

 quently its locality was far beyond the bounds of our system, at a remote distance in the 

 region of the fixed stars. The appearance of a, new star had been observed in Europe 

 about three centuries previous, and such occurrences are mentioned by the ancients ; but 

 this taking place in a comparatively enlightened age naturally excited serious observation 

 and inquiry. The idea of the Danish astronomer, never happy in his philosophical spe 

 culations, was not very fortunate. He supposed that it was produced by a condensation 

 of the matter collected in the Via Lactea, in which it was situated. 



The appearance of a comet in 1577 was industriously watched by Tycho, and he was 

 led to some important conclusions. Unable to detect any sensible parallax, it became 

 obvious that these bodies move at a remote distance from the earth, and were not, accord 

 ing to the common opinion of the times, sublunary objects ; and observing the spheres of 



