Electric Generators. 67 



druggist trusted me for a half pound of " blue 

 vitriol," and I put it into my battery and filled 

 it with water. I waited awhile for it to dis- 

 solve, end then connected my magnet in cir- 

 cuit, when to my astonishment and delight 

 it would lift a pound or more. It was a great 

 triumph. I never have had one since that 

 ^avi me the same satisfaction. But I had my 

 triumph all to myself. I was still the same 

 " tinker" (a name I had long carried), and a 

 nuisance to be endured but not encouraged. 



The dynamo is the form of generator now in 

 general use where heavy currents of electricity 

 are needed. It is aptly described by a writer 

 in Modern Machinery, Mr. John A. Grier, as 

 a thing that when " at rest is a lifeless piece 

 of mechanism ; in action it has a living spirit 

 as full of mystery as the soul of man." This 

 is a poetic way of describing it that conveys to 

 the mind a sense of the power and beauty of 

 natural law in action, that would not come 

 from a mere recital of the cold scientific facts. 

 The facts, however, are necessary: but let us 

 draw from them all the poetry and all the 

 practical lessons that we can as we go along; 

 for it is tliis Mending of the poetic with the 

 practical thai lends a charm to our every-day 

 "jrrind," and lightens the load of many a 

 weary hour. 



The dynamo is a machine that converts 

 mechanical into electrical energy, and tin- 



