258 PHYSICAL SCIENCE 



XXVI 



1 To prove my point I might have used, somewhat un- 

 fairly perhaps, the authority of the great writers who 

 relate that Egypt never experienced an earthquake 

 shock, the reason they allege for it being that it is 

 all composed of mud. If one may believe Homer, 

 Pharos used to be as far from the mainland as a ship 

 under full sail could reach in a day's voyage ; but it 

 has now become attached to the mainland. The 

 Nile's swollen stream brings down great quantities of 

 mud, and by adding it from time to time to the existing 

 land it has by an annual increase constantly carried 



2 forward the coast of Egypt. The country thus is 

 composed of rich loamy soil without interstices, as 

 it has become solid just by the drying up of the mud. 

 The composition of the mud was close and firm, 

 the particles of it being stuck together ; no vacant 

 space could intervene, since the solid was always 

 being added to by the liquid and soft slime. 

 But Egypt is, as a matter of fact, subject to earth- 

 quake ; and Delos, too, though Virgil bade it stand 

 fast, 



And granted that it should be a settled land of tillage, and should 

 laugh the winds to scorn. 



The philosophers, too, a credulous set of people, 

 relying on Pindar's authority, said that it did not 

 experience movement. Thucydides asserts that 

 in former times it was unshaken, but sustained a 

 shock about the time of the Peloponnesian War. 



3 Callisthenes asserts that the same thing happened 

 on another occasion also. Among the numerous 

 portents these are his words by which warning was 



