168 THE GREEK ASTRONOMY. 



tant; 26 Germanicus Caesar, one of the sons-in-law of Augustus, also 

 translated the poem, and this translation remains almost entire. Finally, 

 we have a complete translation by Avienus. 27 The " Astronomica" of 

 Manilius, the " Poeticon Astronomicon" of Hyginus, both belonging 

 to the time of Augustus, are, like the work of Aratus, poems which 

 combine mythological ornament with elementary astronomical expo- 

 sition ; but have no value in the history of science. AYe may pass 

 nearly the same judgment upon the explanations and declamations of 

 Cicero, Seneca, and Pliny, for they do not apprise us of any additions 

 to astronomical knowledge ; and they do not always indicate a very 

 clear apprehension of the doctrines which the writers adopt. 



Perhaps the most remarkable feature in the two last-named writers, 

 is the declamatory expression of their admiration for the discoverers of 

 physical knowledge ; and in one of them, Seneca, the persuasion of M 

 boundless progress in science to which man was destined. Though 

 this belief was no more than a vague and arbitrary conjecture, it sug- 

 gested other conjectures in detail, some of which, having been verified, 

 have attracted much notice. For instance, in speaking of comets, 28 

 Seneca says, " The time will come when those things which are now 

 hidden shall bt brought to light by time and persevering diligence. 

 Our posterity will wonder that we should be ignorant of what is so ob- 

 vious." " The motions of the planets," he adds, " complex and seem- 

 ingly confused, have been reduced to rule ; and some one will come 

 hereafter, who will reveal to us the paths of comets." Such convic- 

 tions and conjectures are not to be admired for their wisdom ; for 

 Seneca was led rather by enthusiasm, than by any solid reasons, to en- 

 tertain this opinion ; nor, again, are they to be considered as merely 

 lucky guesses, implying no merit ; they are remarkable as showing 

 how the persuasion of the universality of law, and the belief of the 

 probability of its discovery by man, grow up in men's minds, when 

 speculative knowledge becomes a prominent object of attention. 



An important practical application of astronomical knowledge \vas 

 made by Julius Caesar, in his correction of the calendar, which we 

 have already noticed ; and this was strictly due to the Alexandrian 

 School : Sosigenes, an astronomer belonging to that school, came 

 from Egypt to Rome for the purpose. 



26 Two copies of this translation, illustrated by drawings of different ages, one 

 set Roman, and the other Saxon, according to Mr. Ottley, are described in the 

 Arc/uiologia, vol. xviii. 



27 Montucla, i. 221. 2S Seneca, Qit. X. vii. 25. 



