202 PHYSICAL SCIENCE BK. v 



after the rise of the Dog-star, because by that time 

 a great part of the cold northern exhalations has 

 been.carried down to our regions. But when the sun 

 has changed his course he still directs his beams 

 straight down on our hemisphere ; and one part of 

 the airj he attracts, but another he thrusts before 

 him. 1 Thus the blast of the Etesians breaks the 

 force of the summer heat, protecting us from the 

 full severity of the most broiling months. 



XI 



I MUST now, as I promised, tell you why the Etesian 

 winds do not give any assistance to their advocates 

 nor contribute aught to their argument. We have 

 said that the breeze is stirred by the morning light, 

 but it no less surely subsides when the full sun has 

 touched it. And yet the Etesians are called by sailors 

 sleepy-headed and dainty, for the very reason that, as 

 my brother Gallio puts it, they cannot get up in the 

 morning. They begin to show face at the time when 

 even the most persistent morning breeze has fallen. 

 This would not occur if the sun reduced the force 

 of the Etesians as he does that of the morning 

 breezes. Add also that, if the cause of their rise 

 was the lengthened space of the day, they would 

 blow even prior to the solstice when the days are at 

 their longest, and when the thaw of the snow is at 

 its height. By the month of July everything is 

 clear of snow, or, at any rate, very few places are 

 still covered with it. 



1 The meaning is very obscure. The text has been suspected, not 

 without cause : the words &quot; he still . . . hemisphere &quot; are out of place, to 

 say the least of it. 



