The theory of the electric installation is then very simple. The valley falls rapidly. At the part selected it falls about 400 feet in 6½ miles. Some of the water is taken out and kept at about the same level so that at the end of the 6½ miles it has a fall of 401 feet. Consequently when it is dropped those 400 feet it falls with immense force and velocity. By most ingenious machinery this force is turned into electrical energy, and then transmitted by wires to wherever wanted--it is hoped even to the plains of the Punjab, to Rawal Pindi at least.
Meanwhile the water, after fulfilling its mission, returns into the river, and might, if need be, be taken out again, led along the mountain-side, and a few miles lower down dropped once more on to another electrical installation, and generate still more electrical energy. The same lot of water might, in fact, go on performing the same duty time after time till the plains of India were reached. Then when it got on to the level, and there was no further fall, it would be impossible to utilise it for generating electrical energy. But it would promptly be seized for another equally important purpose. For it would be caught in the great new canal which is being constructed at the point where the Jhelum River emerges from its mountain barriers and enters the plain; and from that point it would be led over some hundreds of miles to irrigate rich, but as yet uncultivated lands, only needing the touch of life-giving water to burst forth into luxuriant vegetation and attract great populations to them.
The latent capacity for good of these waters of the Jhelum, now tossing heedlessly about as they rush along beside the road into Kashmir, is then for practical purposes almost unlimited. Even the present installation only takes out a small proportion, and that portion is utilised only once. In the driest season the Jhelum River runs with a volume of about 5000 cubic feet per second--what are known for short as "cusecs." But of this amount only 500 cusecs are taken, and these 500 cusecs are utilised only once, and not several times, as they might well be in their fall between the valley of Kashmir and the plains of India.
With these 500 cusecs electrical energy to the extent of 20,000 horse-power will be generated; but Major de Lotbinière thinks that it would be possible to economically develop an aggregate of at least 250,000 horse-power of electrical energy from the Jhelum River. It is not possible to take out water and conduct it along the mountain-side at any point. It is indeed a matter of some difficulty to choose a site where safe headworks can be constructed to entrap the water of the river, where the water can be taken along the hill-side, and where a forebay or tank can be built from which to lead off the pipes to the generating station below. In many parts the river runs between precipitous banks so that it is impossible to get it out. In others, even when it had been got out, the hill-sides would be found so loose and unsafe it would be impracticable to take a water-course along them. Still, in spite of the many difficulties in the way of making practical use of the water-power in the Jhelum River, Major de Lotbinière still thinks that, as above mentioned, electrical energy to the extent of a quarter of a million horse-power could be economically developed.