40 History of Luminescence 



It is very natural that the aurora borealis should be regarded as 

 an omen. Famous occurrences will be found in the writings of the 

 Roman, Julius Obsequens (fl. end fourth century?) , whose De Pro- 

 digiis Liber ^°^ has been published and annotated by a number of 

 later writers such as Conrad Lycosthenes (1552, and subsequent 

 editions up to 1772) and J. Schaffer (1679) . Obsequens' account 

 of the heavens seen on fire (Chap. 13) , nights that shine (Chap. 43) , 

 and burning torches in the sky (Chap. 88) are clearly displays of 

 the aurora. These omens were always accompanied by disaster or 

 followed by pestilence. 



Sea Phosphorescence in Classical Literature 



The earliest reference to the light of the sea "° appears to come 

 from one of the Greek philosophers, Anaximenes (fl. 500 b. c.) , a 

 casual statement with no attempt to investigate the phenomenon. 

 ln2ic\\2i^tGr oi his Natural Philosophy (London, 1807) dealing with 

 the " History of Terrestrial Physics," Thomas Young has written 

 that Anaximander (610-546 b. c.) explained thimder and lightning 

 as the violent bursting of clouds, which he thought were like bags 

 filled with a mixture of wind and water. Young continued: " The 

 same mistaken notion was entertained by Anaximenes, who com- 

 pared the light attending the explosion to that which is frequently 

 exhibited by the sea, when struck with an oar." 



Almost an identical statement was made by Aristotle. In his dis- 

 cussion of lightning in the Meteorologia, the following passage 

 occurs: "^ 



Some— Cleidemus is one— say that lightning is nothing objective but 

 merely an appearance. They compare it to what happens when you 

 strike the sea with a rod by night and the water is seen to shine. They 

 say that the moisture in the cloud is beaten about in the same way, 

 and that lightning is the appearance of brightness that ensues. 



^"'According to de Mairan (L'Aiirore boreale, 162, 1733), Chapters 1 to 55 and a 

 few others are by J. Obsequens, the remainder in the style of Conrad Lycosthenes. 

 For example. Chapter 43 reads: " Two suns were seen, and light throughout the 

 night. At Setia, a torch seemed to be stretched from east to west. A door at Tarracina, 

 and in fact both a door and a wall at Anagnia, were struck by lightening. From the 

 temple of Juno, a frightful crashing noise came out." In practically all the de- 

 scriptions, the last events recorded have to do with war, in this case, devastations in 

 Africa involving Scipio and Hannibal. 



^^'' It has been claimed (G. Hartig, 1861) that a reference to phosphorescence of the 

 sea occurs in the fifth century b. c. voyage (Periplus) of the Carthaginian king, Hanno, 

 to the Libyan regions south of the Pillars of Hercules. Hanno's " fiery torrents " prob- 

 bably referred to burning grass on the hills of Sierra Leone. 



^^^ The E. W. Webster translation of Meteorologia (Book II, Sec. 9) , 370a, Oxford 

 Univ. Press, 1923. 



