Page:Popular Science Monthly Volume 52.djvu/758

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strated than anywhere else. At Redlands, California, there is a plant that delivers the power at a distance of over twenty miles. At Fresno, California, over two thousand horse power is transmitted about thirty-five miles. A noticeable feature of this last-named installation is the enormous height of the water fall. The head is fourteen hundred and ten feet, which is the greatest in use, commercially, in any part of the world. What such a head really means can be realized when we state that the pressure of the water amounts to over six hundred pounds to the square inch. The distance of transmission, thirty-five miles, is also the longest now in actual use, but it is less than that of the Pioneer Electric Company of Ogden, Utah, which is in process of construction. The work now under way at this latter place will transmit power to Salt Lake City, a distance of thirty-six miles, but it is intended to carry the line to mines thirty miles beyond this point; therefore, when the whole system is completed, the total distance of transmission will be sixty-six miles.

The Folsom-Sacramento power-transmission plant is one of the most noteworthy of those so far installed, as it serves to show clearly the great benefits derivable from the use of electricity. The power station is located at Folsom, on the American River, where one of the largest water powers in the State of California is available. The first attempt to utilize this power was made as far back as 1866, but owing to the conditions then existing was necessarily limited in its capacity to the demands of the immediate vicinity. The work as at first conceived embraced a dam across the river, the water to be used in part for power and in part for irrigation purposes. The plan was modest in its proportions, and remained so for many years; but the development of electric transmission has magnified it into an undertaking of vast magnitude, embracing the development and transmission of over five thousand horse power when the full capacity is reached. The dam now used is six hundred and fifty feet long and eighty-nine feet high, and has a storage capacity of about thirteen million cubic yards. The water is conveyed to the water wheels by canals two miles long and fifty feet wide by eight feet deep.

The power station in which the wtaer wheels and the electric generators are located is so designed that the latter are connected direct with the former, being mounted upon the same shafts, but separated from each other by a stone wall, through which the shafts pass. The electric current developed in this station is transmitted to Sacramento, a distance of about twenty-five miles, and is there received in a substation, the interior of which is shown on page 733. The current coming into this station from the power plant is of a very high pressure, entirely too high for commercial use, and there-