CHAP. XII.] EXPERIMENTAL PHYSICS. 355 



course of Experimental Physics, and the erection of 

 the Devonshire Laboratory. 



The following passage is especially characteristic : 



Science appears to us with a very different aspect after 

 we have found out that it is not in lecture-rooms only, and 

 by means of the electric light projected on a screen, that we 

 may witness physical phenomena, but that we may find 

 illustrations of the highest doctrines of science in games and 

 gymnastics, in travelling by land and by water, in storms of 

 the air and of the sea, and wherever there is matter in 

 motion. 



This habit of recognising principles amid the endless 

 variety of their action can never degrade our sense of the 

 sublimity of nature, or mar our enjoyment of its beauty. 

 On the contrary, it tends to rescue our scientific ideas from 

 that vague condition in which we too often leave them, 

 buried among the other products of a lazy credulity, and to 

 raise them into their proper position among the doctrines in 

 which our faith is so assured that we are ready at all times 

 to act on them. Experiments of illustration may be of 

 very different kinds. Some may be adaptations of the 

 commonest operations of ordinary life ; others may be care- 

 fully arranged exhibitions of some phenomenon which occurs 

 only under peculiar conditions. They all, however, agree in 

 this, that their aim is to present some phenomenon to the 

 senses of the student in such a way that he may associate 

 with it some appropriate scientific idea. When he has 

 grasped this idea, the experiment which illustrates it has 

 served its purpose. 



In an experiment of research, on the other hand, this is 

 not the principal aim. . . . Experiments of this class those 

 in which measurement of some kind is involved are the 

 proper work of a physical laboratory. In every experiment 

 we have first to make our senses familiar with the pheno- 

 menon ; but we must not stop here, we must find out which 

 of its features are capable of measurement, and what mea- 

 surements are required in order to make a complete specifi- 



