EFFECTS OF VAGRANT ELECTRICITY. 363 



plication to old work is almost prohibited by the atteiiduiit 

 expense. 



Attacking the problem from a directly opposite standpoint, 

 there seems to be a chance of successfully invoking the aid of some 

 purely chemical method of rendering lead and iron innocuous, elec- 





Lead Service Pipe illustrating the Local Effects of Eight Months' Electrolysis. 

 The other side of this pipe is smooth and clean. 



trolytically speaking. If we can obtain an insulating oxide, lac- 

 quer, or varnish that will retain its high-resistance properties dur- 

 ing the ordinary lifetime of the buried metal, it will be possible to 

 effectually protect pipes and cable coverings by coating them prior 

 to burial. Or, if we can stumble upon an electrolysis-proof alloy, 

 formed by the addition of a few per cent of some foreign metal to 

 the pipe material during manufacture, the buried conductor will 

 need no protection whatever. 



But, supposing that we discover this lacquer or this alloy and 

 by such means guard against damage to all new construction, how 

 are we to care for the metals already buried? We can not dig 

 them all up and paint them, neither can we attempt to replace 

 them by the new alloy. I do not see that the state of the art 

 to-day presents any solution of the difficulty, other than the ban- 

 ishment of the single trolley system. None of the electrical reme- 

 dies (so called) offers more than partial and temporary relief, and 

 the chemical field is just beginning to be explored. 



Permit me to state most emphatically that this is not intended 

 as an argument in favor of the abolishment of single trolley sys- 

 tems. Our civilization owes more to them than could be rehearsed 

 in catalogue form within the limits of one issue of this magazine. 

 We have nothing at present that can be employed as a satisfactory 

 substitute for the ordinary electric railway. The underground 

 trolley is a safe substitute, but the great expense of installation 

 renders it available for very few localities. The overhead trolley, 



