74 PHYSICAL SCIENCE BK. 11 



own recollection during the second consulship of 

 Valerius Asiaticus. 



5 Why have I narrated these incidents ? My 

 purpose was to make it evident that neither is 

 fire necessarily extinguished by having the whole 

 sea poured over it, nor its violence prevented 

 from bursting out by the weight of huge waves. 

 Asclepiodotus, a pupil of Posidonius, has left it 

 on record that the height to which the fire 

 mounted, after overcoming the resistance of the 

 waves, was a hundred fathoms. Now, if such a 

 huge mass of water was unable to overcome the 

 force of the flames that rose from its depths, how 

 much less can the thin, dewy moisture in the clouds 



6 extinguish fire in the atmosphere ? In short, the 

 moisture of the clouds is so far from presenting any 

 obstacle to the formation of fire that lightning is 

 never seen to flash except when the sky threatens 

 rain. A clear sky has no bolts to hurl. No terror 

 of that sort proceeds from a bright day, nor for the 

 matter of that from a night that is not enveloped in 

 cloud. But what ! I hear some one say. Does it 

 not sometimes lighten in a calm night when the 



7 stars are visible? It does, but you must remember 

 that there are clouds all the same in that quarter 

 whence issues the flash ; only, the earth's hump 

 does not allow them to be seen by us. Add, too, 

 what is quite possible, that low clouds near the 

 earth may produce fire through friction. This fire 

 when forced up to the upper regions becomes 

 visible in the clear bright part of the sky, but none 

 the less its place of origin was in the dark vicinity 

 of earth. 



