Van Dam

“ Van Dam watched him curiously. He looked up, at length, to meet Roly's gaze. His own eyes were wavering; his face was distorted with mingled fear and eagerness. He stretched his neck, as if he already felt on it the fingers of his cousin Emile. When Van Dam did not offer to help him he whined: "He has always intended to even up the score; but I am an old man. My hand is unsteady. Perhaps you—It would be worth something to escape those dreams! I could afford to pay well, as you know. You are a strong man. You have no nerves ”

“ It is little more than a step—indeed a step in the literal sense—up to the fertile territories on the north of Lake Van. Ready access is always forthcoming through the Bitlis passage to the Mesopotamian lowlands. The Mush plain represents a considerable subsidence of the plateau region, the average elevation being only 4200 feet. Thence you pass across the dam formed by lavas from Nimrud to the much higher level of Lake Van (5637 feet) . ”

“ Think of the huge bulk of water held up when the reservoir is full. Then you will understand something of the difficulties of the work. Solidity and strength could not but be the first and overpowering idea in the minds of the builders. The longer you look, the more you are impressed. The vast dimensions of the Dam grow upon you from moment to moment. There is, after all, a fierce beauty in those uncompromising features, grimly set in the determination to hold the river in bondage. The massive structure is in harmony with the forces of Nature. ”

“ Dams situated upon the main drainage lines of large catchment areas are usually built of stone or concrete masonry, and designed with large sluiceways and spillways for the discharge both of silt and flood waters. It need scarcely be remarked that, as a rule, such sites are wholly unsuited to earthwork construction. It is said, however, that “every rule has at least one exception,” and this may be true of those relating to dam sites, as will appear later under the head of new types. ”

“ It is a huge granite barrier a mile and a quarter long. There is now a roadway guarded by walls on its top, and there is a miniature railway, the cars of which are pushed by men from one end to the other. The dam serves as a bridge as well, and donkeys, camels, and men are allowed to pass over it from bank to bank. I crossed on the car at a cost of twenty-five cents, my motive power being two Arab boys who trotted behind.
As I came over, I stopped from time to time to examine the construction. The dam is made of big blocks of red granite as fine as that of any tombstone in the United States. ”

“ John C. Frémont, the explorer, indicated the spot as the scene of a disaster where these adventurers suffered the wreck of their boats and the loss of many belongings in the rapids of the river. Hence the name Pathfinder dam. This is a beautiful structure of huge granite blocks 225 feet high and 600 feet long on top, and its cost was $1,000,000.
SHOSHONE RESERVOIR, WYOMING
Judged from the service it has rendered mankind already, as a preventive against disastrous floods and a guarantor of generous harvests, it deserves a high place among the storage structures of the world. ”

“ Now, as Sim Gage topped the grade, gravel crunching under his feet, a trifle out of breath with his climb, since the incline itself was a thing of magnificent distances, he saw the searchlight of the power dam begin a performance altogether new in his own experience.
The great shaft of light rose up abruptly to a position vertical, a beam of light reaching up into the sky. An instant, and it began to swing from side to side. It swung sharply clear against the bald face of the mountain at the farther end of the dam. It swept down the canyon itself, or to its first great bend. ”

“ Any portions which become exposed to the sun and weather are likely to crack and give rise to percolation. Thus a reservoir formed by the construction of a dam resting on the surface of the ground may be more or less water-tight according to circumstances. There are many which are sufficiently water-tight. But in most cases the dam—or an impervious core-wall—is carried down to an impervious stratum. A masonry dam is carried down to rock. ”

“ The night rise in the river had already set in, and the slumped section of concrete had left a broad gap through which the water threatened to pour, endangering not only the power-house directly beneath it, but also the main structure of the dam itself.
The stagings were black with men hurrying back and forth under the glare of the electrics, and the concrete gangs were laboring frantically to clear the wreck made by the crumbling mass, to the end that the carpenters might bulkhead the gap with timbers and planks to hold back the rising flood. ”

“ The Munch brothers built a store and made other improvements. John G. Randall, in 1856-7-8, manufactured lumber, ran it down the Kanabec and St. Croix rivers to Rush Seba, Sunrise and Taylor's Falls. In 1852, and soon after the building of the government road to Superior City, a post office and a stage route from St. Paul to Superior City were established. The dam, to which reference has been made, was built in 1848, by Elam Greely. It is at the outlet of Cross lake and has ten feet head. The flowage covers many thousands of acres. The ownership has changed several times. ”

“ The face of the giant dam, more solidly coherent than granite itself, slowly, grandiose even in its ruin, passed out and down in a hundred foot crevasse where the spill gates were widened by the high explosive. A vast land slip, jarred from the cut-face mountain side above, thundered down and aided in the crumbling of the dam. A disintegrated mass of powdered concrete fell out, was blown apart. The face of the dam on that part slowly settled down into a vast U. Then the waters came through, leaping—a solid face of water such as no man may comprehend. ”

“ It is also more easily raised and strengthened—though this operation has also been effected on masonry dams—in case, for instance, of the silting up of the reservoir, a process which is slow in 164 England, but not so slow when water containing much silt is dealt with, as in the case of irrigation reservoirs in India. Sometimes a dam consists of a wall of masonry or concrete with earth behind it as a support. Whatever kind of dam is used, its construction always demands very great care. Serious disasters, with much loss of life, have occurred owing to failures of dams. ”

“ Human foresight had not made allowance for these record floods, and the temporary dams were beginning to rock and tremble ominously.
"I don't like it," one of the engineers whispered to Hugh. "If much more water comes down, we shall have to anticipate events and turn the Gwilt back into its proper channel. A few hundred pounds of dynamite would do that; in fact, the explosion of the dynamite by electricity is precisely what Royalty will have to do. Then the water flows into the valley, and yonder big dam forms the lake. ”

“ It will be seen from the above description that the point of attack on the dam would naturally be where the pressure is greatest, also at the locks, which would make a mighty channel for the flood of water, and which would be difficult to repair. The spillway, too, if enlarged by explosives, would make a nasty hole to build up.
Now another point which Ned had considered when he looked over the crude drawings he had discovered. Hard rock underlies the dam near the surface of the ground except for about one-fifth of its entire length. ”

“ An abundance of water delivered by gravity under high pressure is usually regarded as one of the essential factors in hydraulic-fill dam building, but it is not essential that there be a large continuous flow. The Lake Frances Dam, recently constructed for the Bay Counties Co., of California, by J. D. Schuyler, is 75 ft. high, 1,340 ft. long on top, and contains 280,000 cu. yds. The dam was built up by materials sluiced by water that was forced by a centrifugal pump through a 12-in. ”

“ The ascent is now more difficult, the path more abrupt and uneven, following the burn, which runs{52} through a deep mountain gorge, showing many different kinds of strata and stone interesting to those who go about with small hammers. At the mill dam you reach a height of 1200 feet. You may be tempted to strike across a flat space to the left and mount by the southern shoulder; but although a shorter cut, it is much steeper and more dangerous than the usual path which is to the right, and which you should follow till you reach the sharp ridge of the east shoulder of the mountain. ”

“ Dugdale’s drawing of 1620 seems to show a wall on the upper side of the dam, but of this there is now no visible trace. The broad and level surface of the dam was well suited for a tilt-yard and seems always to have been so employed, as was also, no doubt, the Brayz. Such exercises, being attended by numbers of armed men, were usually held at the barriers, or outside the main gate of the castle, as a precaution against a surprise. The effect of the dam was to form a sheet of water 90 yards to 100 yards across, half a mile long, 10 feet to 12 feet deep, and covering about 111 acres. ”

“ To-day she has advanced well past the half million population mark. Although as regards her [110] foreign trade she does not profess to compete with Rotterdam, as a money market and clearing house for colonial products she is preëminent in the Netherlands.
The Dam—a large square that owes its name to the fact of its being the eastern boundary of Lord Amstel’s embankment across the river—is the axis around which Amsterdam revolves. It is literally the hub of the Dutch universe. Every electric car in the place starts from the Dam, and in due course of time will wind its way back again. ”

“ What a to-do about building a dam they make! They must have government backing, and political wirepulling, and they must fiddle around for years with hundreds of men building a dam up from bedrock, with cement and stone! Wait until I show you what we mean to do! Simplest thing in the world—since we don’t want canals for irrigation and only want to get at the river below. Even if we did want to divert the water, instead of restraining it only, we could build our canals just the same, and at our leisure. ”

“ The government's argument recognizes this essential limitation. The government's contention is that the Wilson Dam was constructed, and the power plant connected with it was installed, in the exercise by the Congress of its war and commerce powers (Const. art. 1, § 8, cls. 3, 11) ; that is, for the purposes of national defense and the improvement of navigation.
Wilson Dam is described as a concrete monolith one hundred feet high and almost a mile long, containing two locks for navigation and eight installed generators. Construction was begun in 1917 and completed in 1926. ”

“ The lofty concrete barrier which backs up Long Lake has the distinction of being the highest spillway dam in the world. The “Spokane interval” proved a highly enjoyable spell of relaxation before tackling the rough stretch of river ahead. I knew I was going to miss greatly the guiding hand and mind of Captain Armstrong, but had high hopes of Ike Emerson. ”

“ These rubble dams were well tested when the high Nile ran over them; and on work being resumed in November, after the fall of the river, water-tight sandbag dams or sudds were made around the site of the Dam foundation in the still waters above the rubble dams, and pumps were fixed to lay dry the bed of the river. This was the most exciting time in the whole stage of the operations, for no one could predict whether it would be possible to dry the bed, or whether the water would not pour through the fissured rock in altogether overwhelming volumes. ”

“ Since it has been built the yearly tax revenues have gained by two million dollars, and the lands owned by the government have become worth five million dollars more.
The dam is also more wonderful than the Pyramids in its construction. Old Cheops is built on the edge of the [134] desert on a solid stone platform, and is little more than the piling of one stone upon another. For the Aswan Dam a trench a hundred feet wide and a hundred feet deep had to be excavated in the granite rock. ”

“ A curious fact we noted, was, that while both banks of the river were strewn with fragments of the old dam, not a single piece of this tainted and dangerous material was used. New trees and bushes were cut and carried greater distances for the rebuilding.
At this stage of the war, Bige and I surrendered. We were hopelessly outnumbered and outclassed by the beavers. They worked while we were asleep. We now got busy and cut out a new trail around the swamp and the flooded area to connect with the old trail. This makes the walk fully a half mile longer than before the dam was built. ”

“ The camp of the reclamation engineers and construction men lay upon a bench or plateau which once formed the bank of the stream upon that side, now about half way up to the top of the great dam. The road running up and down the valley ascended from this plateau to a sufficient elevation to surmount the permanent water level above the upper dam. On the opposite side rose a sheer and bare rock running two-thirds up to the top of the mountain peak which here had shouldered its way down as though in curiosity to look at the bottom of the gorge itself. ”