Abstract :
The last 50 years is the epoch of electric lighting, says Electrical World editorially, for this kind of lighting began only half a century ago. It is commonplace to remark that the cost of light today from tungstenfilament lamps is only a small portion of the cost of the same quantity of light fifty years ago; but how many grasp the enormous difference? If the unskilled laborer of a half century ago had used as much light as is now used daily in the average home in this country, he would have had to work two and one-half hours daily to pay his gas-lighting bill alone, as compared with approximately ten minutes daily for the average unskilled laborer to pay his present electric lighting bill.