Of course this can never be practicable. Much power will always be needed where no stream for power is available. But the lesson is plain that where water can be used it should be, both in order to save the coal and because it can be produced more cheaply. The 30,000,000 horse-power now available, if produced in our most modern electric plants, would require the burning of nearly 225,000,000 tons of coal, and if in the average plant run by steam-engines, more than 650,000,000 tons of coal, which is fifty per cent. more than all the coal that is now produced in this country. At three dollars per ton it would cost $2,000,000,000 a year to supply the coal to furnish the power that we might have, one might almost say, as a by-product from the improving of the rivers for navigation. The development of the water-power possibilities of the country is now going forward at a rapid rate, however. Dams on the Susquehanna River will soon make 30,000 horse-power available, which could be increased to 200,000 by building storage reservoirs. A dam just begun at the rapids of the Mississippi River at Keokuk, Iowa, will, when completed, furnish 200,000 horse-power. Niagara is producing 56,000 horse-power on the United States side. The Muscle Shoals Falls rapids in the Tennessee River is furnishing 188,000 horse-power. Illinois will greatly increase its possibilities for offering cheap power to factories, when the Lakes to Gulf Canal with 173,000,000 horse-power worth $12,750,000 yearly, and the Chicago Drainage or Sanitary Canal, which has nearly 60,000 horse-power, are complete. Both of these projects were undertaken by the state. In California 250,000 horse-power is now in operation, and 5,000,000 horse-power might easily be developed in that state alone, which at the price of coal would be worth a billion dollars a year. New England has the oldest system of water-power control, because before the era of steam it was the chief manufacturing region of the country. The Merrimac, flowing through New Hampshire and Massachusetts, is the most carefully conserved river in the world, and Governor Dingley of Maine said that the water-power of Maine is equal to the working energy of 13,000,000 men. The money value is counted at twenty dollars a year per horse power, but it frequently brings as high as one hundred or even one hundred and fifty dollars a year in a good manufacturing region, so that the value of our water-power facilities can hardly be computed.