276 PHYSICAL SCIENCE BK. vn 



line of fire, which lasts just so long as the mass 

 of air remains, which carries within it the supply of 

 moist earthy matter. 



1 THIS account of Epigenes is a tissue of falsehoods. 

 To begin with the nearest one, the last, it is not true 

 that torch and beam meteors are due to the violent 

 action of a whirlwind. The whirlwind is formed 

 in the neighbourhood of the earth, and there it runs 

 its course. This is the reason why it tears up trees 

 by the roots, and wherever it swoops down it lays 

 bare the soil, carrying off in the meanwhile woods 

 and roofs of houses ; as a rule, it is lower than the 

 clouds, and assuredly never higher. But, on the 

 contrary, it is the more exalted part of heaven that 

 displays beam meteors, and so they never intervene 

 between us and the clouds. Besides, a whirlwind 

 is borne along more swiftly than any cloud, and 



2 rotates as on a pivot. And in addition to this, it 

 ceases all of a sudden, bursting by its own force. 

 " Beams," on the contrary, do not run or fly across, 

 like torches, but remain shining for some time 

 in the same quarter of the sky. Charimander, 

 too, in the book he wrote on comets, asserts that 

 a great and unusual light in the sky of the size 

 of a large beam was once seen by Anaxagoras, 

 and continued to shine for a long period. Callis- 

 thenes puts it on record that a similar appearance, 

 of a trail of fire was observed before the sea 



3 swallowed up Buris and Helice. Aristotle says it 

 was not a " beam," but a comet ; the characteristic 

 dispersion of the fire was not seen at first on 

 account of its excessive brightness, but, in process 



