SCIENCE AND PRACTICAL NEEDS 5 



Egyptian geometry cared little for theory. It ad- 

 dressed itself to actual problems, such as determin- 

 ing the area of a square or triangular field from the 

 length of the sides. To find the area of a circular 

 field, or floor, or vessel, from the length of the diame- 

 ter was rather beyond the science of 2000 B.C. This 

 was, however, a practical problem which had to be 

 solved, even if the solution were not perfect. The prac- 

 tice was to square the diameter reduced by one ninth. 



In all the Egyptian mathematics of which we have 

 record there is to be observed a similar practical bent. 

 In the construction of a temple or a pyramid not 

 merely was it necessary to have regard to the points 

 of the compass, but care must be taken to have the 

 sides at right angles. This required the intervention 

 of specialists, expert " rope-fasteners," who laid off a 

 triangle by means of a rope divided into three parts, 

 of three, four, and five units. The Babylonians fol- 

 lowed much the same practice in fixing a right angle. 

 In addition they learned how to bisect and trisect the 

 angle. Hence we see in their designs and ornaments 

 the division of the circle into twelve parts, a division 

 which does not appear in Egyptian ornamentation till 

 after the incursion of Babylonian influence. 



There is no need, however, to multiply examples ; 

 the tendency of all Egyptian mathematics was, as 

 already stated, concerned with the practical solution 

 of concrete problems mensuration, the cubical con- 

 tents of barns and granaries, the distribution of bread, 

 the amounts of food required by men and animals 

 in given numbers and for given periods of time, the 

 proportions and the angle of elevation (about 52) 

 of a pyramid, etc. Moreover, they worked simple 



