Pkksidknt.s Audrkss— Sect. A. 21 



us of ;iny observations made by them, a circumstance profoundly to be 

 rt^grettecl, for \n variable star research the greater the space of time 

 over which careful observations have been made, the more valuable and 

 far-)'eaching the (Unliictions drawn from them. But when a star sud- 

 denly appears in a position of tlic sky where no bright star was ever 

 seen before, nud with such splendour that the light of day was not 

 sufficient to overpower its rays, even the attention of the multitude 

 was claimed by the stranger. Upon the astronomers of their day these 

 new stars had naturalh' a quickening influence. And thus it is that 

 each appearance of these strange visitors heralded some definite ad- 

 vance in astronomical science. 



It is recorded by Pliny that it was the appearance in the constel- 

 lation of the Scorpion of a new star in 124 b.c. which led the great 

 astronomer Hipparchus to draw up his famous catalogue of the stars, 

 the type of every catalogue from his day to ours. He pursued and 

 finished his labour in the hope that if, in the process of the ages, 

 changes took place in the face of the sky, astronomers would be able to 

 detect and define them. 



In 1-572 a brilliant new star appeared in Cassiopeia's Chair, so sur- 

 passingly lustrous that it was clearly visible at noon, to the great 

 terror of many ignorant folk. This star was the means fortunately of 

 turning the attention of the Danish astronomer Tycho Brahe from 

 chemistry to astronomy, and of inducing him to embark on that 

 fine series of observations which in his pupil Kepler's hands yielded the 

 three famous Iveplerian Laws, and yet later in time aided Newton to 

 no inconsiderable extent in the discovery that these three laws of 

 planetary motion were a necessary consequence of one simple compre- 

 hensive law — the law of gravitation. 



A new star in 1604 in the Serpent quickened the zeal of both 

 Kepler and Galileo ; indeed, it is more than probable that it was the 

 appearance of this star which drew the inventive and penetrative mind 

 of the latter to astronomy. 



Up to this date, however, the end of the sixteenth century, no 

 periodic variable stars had been discovered. The new stars recorded 

 before Keplei" or Galileo's day — some six or seven in number — were so 

 transcendently variable that they could not but be observed. 



It ^^as otherwise with the milder pulsations of thousands upon 

 thousands of stars. These remained undiscovered, a sure sign of how 

 little attention was paid by ancient and mediaeval astronomers to 

 individual stars. 



As the sixteenth century was drawing to a close — ^on the 13th 

 August, 1596, to be exact — a diligent amateur in East Friesland, David 

 Fabricius by name, detected a faint star in the Whale, which, by that 

 strange instinct only known to men whose hearts are in their work, he 

 noted as suspicious. Ere the year closed the star had disappeared, 

 and Fabricius regai'ded it as simply another new star which for a 

 brief space had shone in our sky, and then, like its predecessors, had 

 disappeared. 



But in 1603 it was again visible, and of such brightness thq,t 



