Chap. 57.] AiifiA2s-Gi:M£yr or the st^hs. 75 



are deceived in regard tx) them, although endowed with even a, 

 greater degree of sagacity upon these points than we are, from 

 the fact of their very existence depending so materially upon 

 them. Hence it is, that we sometimes see the summer birds 

 killed by too late or too early cold, and the winter birds by 

 heat coming out of the usual season. It is for this reason, 

 that Virgil ^^ has recommended us to study the courses of the 

 planets, and has particularly warned us to watch" the passage 

 of the cold star Saturn. 



There are some who look upon the appearance of the butter- 

 fly as the surest sign of spring, because of the extreme delicacy 

 of that insect. In this present year,^^ however, in which I 

 am penning these lines, it has been remarked that the flights 

 of butterflies have been killed three several times, by as many 

 returns of the cold ; while the foreign birds, which brought 

 us by the sixth of the calends of February ^' every indication 

 of an early spring, after that had to struggle against a winter 

 of the greatest severity. In treating of these matters, we have 

 to meet a twofold difficulty : first of all, we have to ascertain 

 whether or not the celestial phaenomena are regulated by 

 certain laws, and then we have to seek how to reconcile those 

 laws with apparent facts. "We must, however, be more par- 

 ticularly careful to take into account the convexity of the earth, 

 and the differences of situation in the localities upon the face 

 of the globe ; for hence it is, that the same constellation shows 

 itself to different nations at difltrent times, the result being, 

 that its influence is by no means perceptible everywhere at the 

 same moment. This difficulty has been considerably enhanced, 

 too, by various authors, who, after making their observations 

 in difl'erent localities, and indeed, in some instances, in the same 

 locality, have yet given us varying or contradictory results. 



There have been three great schools of astronomy, the Chal- 

 daean, the Egyptian, and the Grecian. To these has been 

 added a fourth school, which was established by the Dictator 

 Caesar among ourselves, and to which was entrusted the duty 

 of regulating the year in conformity with the sun's revolution, ^^ 

 under the auspices of Sosigenes, an astronomer of considerable 

 learning and skill. His theory, too, upon the discovery of cer- 

 tain errors, has since been corrected, no intercalations having 



" Gtorg. L 335. le A.r.c. 830. 



^' Twenty-seventh of Jamiary. i^ Ad solis cursum. 



