212 POPULAR LECTURES AND ADDRESSES. 



of engineering, indeed, is high science more in- 

 telligently appreciated and ably applied than in 

 the manufacture and the use of telegraphic lines, 

 whether over land or under sea ; and it would be 

 quite superfluous for me to speak on that subject 

 to those whom I see before me. 



But I do not know whether so much is thought 

 of what the electric telegraph and its workers have 

 already done, and may be expected yet to do, for 

 science in general, and particularly electricity and 

 magnetism. Time does not allow me to enlarge 

 as I would like to do on this subject. I will 

 merely remind those who are present of the great 

 advance that has been made in accurate measure- 

 ment within the last fifteen years. I need not 

 tell you that a large part of the benefit thus 

 achieved for science is due to the requirements of 

 the practical telegraphist. Men of abstract science 

 were satisfied to know that absolute measure- 

 ment was possible, and that a definition of 

 magnetic force, a definition of electric resistance, 

 a definition of electromotive force, and so on 

 through the list of numerical quantities in elcc- 



