228 FRAGMENTS OF SCIENCE. 
can say what intellectual Samsons are at the present 
moment toiling with closed eyes in the mills and forges 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 
locomotive of which the maker of it probably never 
dreamed, but which nevertheless may be sufficient to con- 
vert 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 suf- 
ficient physical knowledge, from the operatives themselves 
would probably emanate a system by which these shocking 
accidents might be avoided. Possessed of the knowledge, 
their personal 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 diminution of the calamity. 
Before the present Course of Lectures was publicly an- 
nounced, 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 re- 
vealed themselves to my own eyes, and have been enacted 
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 already cited, 
which presented themselves to my notice during my brief 
career as a teacher in the college already alluded to. The 
facts, though extremely humble, and deviating in some 
slight degree from the strict subject of the present dis- 
course, may yet serve to illustrate an educational principle. 
One of the duties which fell to my share was the in- 
struction of a class in mathematics, and I usually found 
that Euclid and the ancient geometry generally, when 
properly and sympathetically addressed to the understand- 
