22 SCIENCE AND THE HUMAN MIND 



squares and cubes, have been found among their 

 tablets. A duodecimal system of units, making the 

 calculation of fractions easy, existed alongside a 

 decimal system. The circle with its subdivisions of 

 angular measurement, the fathom, the foot and its 

 square, the talent and the bushel in fact, the com- 

 plete system of Chaldean weights and measures were 

 based on the parallel use of this double system of 

 notation. 



The beginnings of geometry, too, are found in rudi- 

 mentary formulae and figures for land-surveying, once 

 more illustrating the origin of an abstract science 

 from the needs of everyday life. Plans of fields 

 led to more complicated plans of towns, and even 

 to maps of the world as then known. But actual 

 knowledge was woven in an - inextricable manner 

 with magical conceptions. The ideas of the virtues 

 of special numbers, their connections with the gods, 

 and the application of geometrical diagrams to 

 the prediction of the future, passed from Chaldea 

 westward, and for centuries dominated European 

 thought. 



As agriculture develops among a primitive people, 

 the importance of a knowledge of the seasons grows 

 also. It is a remarkable fact that the great majority 

 of cereals and cultivated food-plants originated either 

 in China and the Far East or at the eastern end of the 

 Mediterranean basin. As the chief part of these plants 

 are annuals, requiring seasonal treatment and ample 

 water-supplies, we have here probably one reason why 

 large centres of population early grew up in the basins 

 of the Euphrates and the Nile, in which great stress 

 was laid on astronomical observation. The cultiva- 



