6i2 THE POPULAR SCIENCE MONTHLY. 



per annum. Not only will the facts be shown relative to the cost 

 per capita of each method of lighting the streets of a city, 

 whether by gas, electric light, or oil, etc., but the relative advan- 

 tages of lighting streets by works owned by the city and works 

 owned by private corporations will be shown. It is a fact that 

 the gas-light is gradually giving place to the electric light ; for, 

 while the facts for the cities named in the tables already pub- 

 lished by the census office show that gas-lamps comprise over 

 sixty per cent of all classes used for street-lighting, it is evident 

 that they are now rarely used exclusively for lighting. It is also 

 learned that electric lighting is most favored in those cities that 

 have less than 100,000 inhabitants each ; for, in 278 such cities, 

 out of a total of 91,667 lamps, 35,127 are gas-lamps, 35,191 are 

 electric lamps, and 21,149 are lamps burning oil, etc. Taking the 

 total cities from which reports have been received relative to 

 light, being 309 cities, with a population of 16,335,569, the total 

 number of lamps of all kinds is 293,847, the gas-lamps numbering 

 182,671, the electric lamps 53,696, and the oil-lamps 57,480. 



The interest which now centers in the question as to whether 

 quasi public works shall be controlled by private corporations or 

 by the municipality itself is illustrated more specifically by the 

 facts connected with water- works than by those surrounding any 

 other character of city works, and the difference as to cost of 

 maintenance and receipts between public and private works is 

 very noteworthy. The facts are already given quite fully by the 

 census for fifty cities, and of these thirty-five own their own 

 water-works. The average cost of construction in the thirty-five 

 cities owning their own water- works to each head of population is 

 $21.35, while in thirteen cities where the water-works are owned 

 by private parties the cost of construction to each head of popula- 

 tion is $31.20, or nearly ten dollars more per capita than where 

 the cities construct their own works. Out of .273 cities reporting 

 to the census on their water-works, fifty-six per cent own and 

 operate their own works, the remainder depending on private 

 companies for their water-supply ; but the fifty-six per cent repre- 

 sent seventy-seven per cent of the total population of the 273 

 cities. A greater proportion of private works perhaps are to be 

 found in the smaller cities ; for, out of 133 such cities, having a 

 population of 3,708,994, 112 cities, representing 2,351,574 people, 

 have their water- works operated by private parties. 



The sewers of the cities of the country are under the control 

 and direction of the municipal governments. The construction 

 has been under public control. In Baltimore, where the sewers 

 are intended for the removal of storm water only, is found the 

 smallest percentage of sewers to streets in the larger cities, it 

 being only 3-56. The cities of Washington and Cambridge have 



