ON THE STUDY OF PHYSICS 815 



of Manchester and Birmingham? Grant these Samsons 

 sight, and you multiply the chances of discovery, and 

 with them the prospects of national advancement. In our 

 multitudinous technical operations we are constantly play- 

 ing with forces our ignorance of which is often the cause 

 of our destruction. There are agencies at work in a loco- 

 motive of which the maker of it probably never dreamed, 

 but which nevertheless may be sufficient to convert it into 

 an engine of death. When we reflect on the intellectual 

 condition of the people who work in our coal mines, those 

 terrific explosions which occur from time to time need not 

 astonish us. If these men possessed sufficient physical 

 knowledge, from the operatives themselves would prob- 

 ably emanate a system by which these shocking accidents 

 might be avoided. Possessed of the knowledge, their per- 

 sonal interests would furnish the necessary stimulus to its 

 practical application, and thus two ends would be served 

 at the same time — the elevation of the men and the dimi- 

 nution of the calamity. 



Before the present Course of Lectures was publicly 

 announced, I had many misgivings as to the propriety of 

 my taking a part in them, thinking that my place might 

 be better filled by an older and more experienced man. 

 To my experience, however, such as it was, I resolved 

 to adhere, and I have therefore described things as they 

 revealed themselves to my own eyes, and have been en- 

 acted in my own limited practice. There is one mind 

 common to us all; and the true expression of this mind, 

 even in small particulars, will attest itself by the response 

 which it calls forth in the convictions of my hearers. I 

 ask your permission to proceed a little further in this 

 fashion, and to refer to a fact or two in addition to those 



