.">4 THE PROGRESS OF SCIENCE n 



craftsmen. But, even while the cries of jubilation 

 resound and this flotsam and jetsam of the tide of 

 investigation is being turned into the wages of 

 workmen and the wealth of capitalists, the crest 

 of the wave of scientific investigation is far away 

 on its course over the illimitable ocean of the un- 

 known. 



Far be it from me to depreciate the value of the 

 gifts of science to practical life, or to cast a doubt 

 upon the propriety of the course of action of those 

 who follow science in the hope of finding wealth 

 alongside truth, or even wealth alone. Such a 

 profession is as respectable as any other. And 

 quite as little do I desire to ignore the fact that, 

 if industry owes a heavy debt to science, it has 

 largely repaid the loan by the important aid 

 which it has, in its turn, rendered to the advamv- 

 ment of science. In considering the causes which 

 hindered the progress of physical knowledge in 

 the schools of Athens and of Alexandria, it has 

 often struck me 1 that where the Greeks did 

 wonders was in just those branches of science, 

 such as geometry, astronomy, and anatomy, which 

 are susceptible of very considerable development 

 without any, or any but the simplest, appliances. 

 It is a curious speculation to think what would 

 have become of modern physical science if glass 



1 There are excellent remarks to the same effect in Zeller's 

 l>hic der Gricchen, Theil II. Abth. ii. p. 407, and in 

 Kuck.'u's Die Methode der Aristotdiyh' n Fvmchuwj, i>p. 138 

 ft *-,. 



