RELATIONS OF CIVIL ENGINEERING 559 



conception, for engineering is truly and almost exclusively the science 

 of construction. The functions of the engineer in all cases either are 

 directly constructive or tend toward construction. 



The engineer has ever had a due appreciation of all the sciences, 

 imagination to see practical possibilities for the results of their 

 findings, and the common-sense power of applying them to his own 

 use. 



Pure science (barring perhaps political economy) is not concerned 

 with financial matters, and its devotees often look down with lofty 

 disdain upon everything of a utilitarian nature, but engineering is 

 certainly the science most directly concerned with the expenditure 

 of money. The engineer is the practical man of the family of scientists. 

 While he is sufficiently well informed to be able to go up into the 

 clouds occasionally with his brethren, he is always judicious and 

 comes to earth again. In all his thoughts, words, and acts he is 

 primarily utilitarian. It is true that he bows down to the goddess of 

 mathematics, but he always worships from afar. It is not to be 

 denied that mathematics is the mainstay of engineering; neverthe- 

 less the true engineer pursues the subject only so far as it is of prac- 

 tical value, while the mathematician seeks new laws and further 

 development of the science in the abstract. The engineer does not 

 trouble himself to consider space of four dimensions, because there 

 are too many things for him to do in the three-dimension space in 

 which he lives. Non-Euclidian geometry is barred from his mind for 

 a fuller understanding of the geometry which is of use to ordinary 

 mankind. The mathematician demonstrates that the triangle is the 

 sole polygonal figure which cannot be distorted, while the engineer, 

 recognizing the correctness of the principle, adopts it as the funda- 

 mental, elementary form for his trusses. The mathematician endea- 

 vors to stretch his imagination so as to grasp the infinite, but the 

 engineer limits his field of action to finite, tangible matters. 



The geologist, purely studious, points out what he has deduced 

 about the construction of the earth; but the engineer makes the mine 

 pay. 



The chemist discovers certain facts about the effects of different 

 elements in alloys; but the engineer works out and specifies a new 

 material for his structures. Again, the chemist learns something 

 about the action of clay combined with carbonate of lime when 

 water is added, and from this discovery the engineer determines 

 a way to produce hydraulic cement. 



The physicist evolves the theory of the expansive power of steam, 

 and the engineer uses this knowledge in the development of the steafn 

 engine. Again, the physicist determines by both theory and experi- 

 ment the laws governing the pressures exerted by liquids, and the 

 engineer applies these laws to the construction of dams and ships. 



