Both these plants are enterprises of Stone & Webster, of Boston. A competitive plant is now nearing completion by the city of Tacoma, utilizing the third of the rivers emptying into the Sound. The Nisqually is dammed above its famous canyon, at an elevation of 970 feet, where its minimum flow is 300 second feet. The water will be carried through a 10,000-foot tunnel and over a bridge to a reservoir at La Grande, from which the penstocks will carry it down the side of the canyon to the 40,000 horse-power generating plant built on a narrow shelf a few feet above the river. The city expects to be able to produce power for its own use, with a considerable margin for sale, at a cost at least as low as can be attained anywhere in the United States.
Hydro-electric plant at Electron, on the Puyallup River, producing 28,000 h. p.
The rocks of which the Mountain is composed are mainly andesites of different classes and basalt. But the peak rests upon a platform of granite, into which the glaciers have cut in their progress. Fine exposures of the older and harder rock are seen on the Nisqually, just below the present end of its glacier, as well as on the Carbon and in Moraine Park. This accounts for the fact that the river beds are full of granite bowlders, which are grinding the softer volcanic shingle into soil. Thus the glaciers are not only fast deforming the peak. They are "sowing the seeds of continents to be."[Back to content]
Cutting canal to divert White River into Lake Tapps.