Epidemics. 289 



but quicker and quite independent of the eccentricity of the 

 earth's orbit. 



For, howsoever we turn about, since the historic age of 

 man, the difference with which the sun's rays have been 

 received on the earth's surface, upon the score of the 

 eccentricity of the earth's orbit, is merely fractional ; and 

 the diurnal amount from year to year on any particular spot 

 of the earth is, from a practical point of view, the same 

 now as it was in the days of Nimrod and Pharaoh I., if 

 anybody knows on what day he ascended the throne in the 

 days of Egyptian greatness. 



Let us look at one or two of the indications of slow and 

 gradual changes of temperature on the earth's surface within 

 the historic period of man. 



Job says that " my brethren have dealt deceitfully as a 

 brook, and as the stream of brooks they pass away; which are 

 blackish by reason of the ice, and wherein the snow is hid."* 



Here the very description indicates ice in a pond, or 

 covering a running stream ; for though snow is white, when 

 water by flowing has covered it and then frozen it in, the 

 whiteness disappears, and a blackish look results. If such 

 a passage as this is given, to illustrate the deceitfulness of 

 character, to the hearers whom Job was reproaching, it 

 cannot be doubted for one moment that both speaker and 

 hearers were perfectly familiar with the fact which is here 

 used as a simile for character. 



To speak of the face of the deep, as in another passage of 

 Job, being as stone and frozen ; and a brook freezing snow 

 in its course and covering it with ice in such a land as 

 Idumea, or Edom, or Arabia Felix appears incredible ; but 

 from 1600 or 1500 B.C. this was a fact well known to 

 the learned in that land, and familiar to a degree that 



* Job vi. 15, 16 ; also see Job xxxviii. 30. 



