PREFACE. 



other vortices. According to this view all our electrical 

 machines and batteries are merely instruments for alter- 

 ing the distribution of Electricity by moving some of it 

 from one place to another, or for causing Electricity, 

 when accumulated or heaped together in one place, to 

 do work in returning to its former level distribution. 

 Throughout these Lessons the attempt has been made 

 to state the facts of the Science in language consonant 

 with this view, but at the same time rather to lead the 

 student to this as the result of his study than to insist 

 upon it dogmatically at the outset. 



UNIVERSITY COLLEGE, BRISTOL, 

 March 1 88 1. 



