ON THE PROGRESS OF ELECTRIC LIGHTING. 17 



But wasted energy may also take the form of leakage, or direct loss of cur- 

 rent. This is cured only by good insulation. Good insulation unfortunately 

 means expense ; and here again competition has forced too much economy. I 

 have not examined one single case of the failure of an electric Hght that has not 

 been traceable either to crass ignorance, or to needless economy. Perfectly well 

 insulated copper conductors are within the reach of all who choose to pay for 

 them ; but when proper specification, proper inspection, and proper tests are 

 neglected, we must expect, as has too often happened, failure and expense. 



A marvellous improvement has been made by Dr. John Hopkinson and by 

 Mr. Edison, independently of each other, by which the weight of copper neces- 

 sary for central station working has been diminished 60 per cent, and this is due 

 to the use of two dynamos connected in series, and a third, or compensating 

 conductor, placed between them. The weight of copper necessary for a conduc- 

 tor can also be diminished by the use of high tension currents, and this has led 

 to various suggestions by which high tension currents shall be used for charging 

 secondary batteries, and for exciting induction coils, but the use of high tension 

 currents for household purposes is at present regarded as dangerous. High 

 tension currents are, however, available for public street lighting, and are very 

 satisfactorily employed for this purpose. There is a very senseless crusade being 

 conducted just now in certain quarters against overhead wires. Overhead wires, 

 if properly constructed, are most desirable, especially for electric lighting. It is 

 the terrible abuse of this mode of construction that has caused the present 

 onslaught upon them. Overhead wires can be made absolutely secure ; they need 

 not be a disfigurement nor an injury; they are far more readily maintained than 

 underground wires ; they facilitate the economy of electric lighting, not only by 

 affording better conductors, but by radiating away the waste heat generated, 

 and by requiring fewer joints and connecting points. 



I do not in the least object to overhead wires through our streets for public 

 lighting, though I strongly object to the cloud of wires that now obstruct the sky 

 line in many of our thoroughfares. When ugly objects form an essential function 

 of utility, it is wonderful how their unsighthness is condoned. Who complains 

 of the ugliness of gas lamp-posts, and what is there in the necessary adjuncts of 

 town life more ungraceful or hideous ? 



I do not, however, advocate overhead wires for general lighting. The con- 

 ductors in that case must go underground, and with the great demand for tele- 

 graphs, telephones, and electric lighting, it is a pity that our corporations do not 

 extend that useful system of subways, that has been partially carried out in the 

 City of London, for easy fixing and inspection. The present mode of laying 

 pipes in trenches is not only costly, but dangerous, and it has led to many more 

 accidents than have been occasioned by the faUing of overhead wires. Our streets 

 are almost always open for either gas, water, telegraphs, or telephones, and the 

 evil is increasing, and will continue to increase, with electric lighting. The cure 

 is proper subways. 



VIII— 2 



