58 LIGHT SCIENCE FOR LEISURE HOURS. 



But side by side with this inquiry, another Lad 

 been in progress. A crowd of diligent laborers had 

 been searching with close and rigid scrutiny into the 

 circumstances attending ancient eclipses. A new light 

 had been thrown upon this subject by the labors of 

 modern travellers and historians. One remarkable 

 instance of this may be cited. Mr. Layard has iden- 

 tified the site of Larissa with the modern Nimroud. 

 ]^ow, Xenophon relates that when Larissa was besieged 

 by the Persians, an eclipse of the sun took place, so 

 remarkable in its effects (and therefore undoubtedly 

 total), that the Median defenders of the town threw 

 down their arms and the city was accordingly cap- 

 tured. And Hansen had shown that a certain estimate 

 of the moon's motion makes the eclipse which occurred 

 on August 15, 310 B. c., not only total, but central at 

 Mmroud. Some other remarkable eclipses as the 

 celebrated sunset eclipse (total) at Rome 399 u. c., 

 the eclipse which enveloped the fleet of Agathocles 

 as he escaped from Syracuse; the famous eclipse of 

 Thales, which interrupted a battle between the Medes 

 and Lydians; and even the partial eclipse which 

 (probably) caused the "going back of the shadow upon 

 the dial of Ahaz " have all been accounted for satis, 

 factorily by Hansen's estimate of the moon's motion ; 

 so, also, have nineteen lunar eclipses recorded in the 

 Almagest. 



This estimate of Hansen's, which accounts so satis- 



