fragments, rode lightly away upon the great wave that had torn it from its foundations. Although the cost of their dam had been about $75,000, the projectors, not dismayed by the first failure, were ready to enter upon the construction of a new dam in the spring of 1849, and were able to complete the work in October of the same year, under the able supervision of Philander Anderson, whose initial training as an engineer was received at West Point. The work, built of timbers and planks bolted together and weighted with rocks and gravel, was facilitated by means of coffer dams extending at first two hundred feet into, the river from either bank, from which others were projected as fast as the permanent structure progressed and the summer ebb of the water favored, until the entire span had been completed. Along the upper part of the permanent structure 46 gates, each 16 feet wide by 18 feet long, had been provided and left open for the escape of the water during construction. When the work was completed, at a given signal, at half-past twelve o'clock, all these gates were simultaneously closed, the pent-up waters rose against the new dam, and the rocky bed of the rapid below once more became bare. Six thousand spectators visited the scene, more than on the former occasion; but the new work had cost about $150,000, and was destined to prove its sufficiency against a lateral pressure of nearly twenty-five million pounds and a vertical pressure three times as great. By ten o'clock the water reached the crest of the dam, and at eleven it had acquired a full head and poured down the perpendicular face in one unbroken sheet, producing at first such heavy vibration's as to rattle windows and doors in South Hadley Falls. A cross section of this dam would exhibit a right-angled triangle, the long leg at the bottom extending horizontally up stream, the short one extending up the face to the crest, and the hypothenuse running down the inclined back of the structure. Twenty years later the work was thoroughly repaired, and a structure similar to the old one was built upon its face, giving the whole the form of an ordinary roof. This substantial work not being of indestructible material, the Water Power Company, according to design, has now in process of erection a dam of solid masonry 1,020 feet long between abutments, down stream from the old one, distant from it 132 feet on the Holyoke side and 112 feet on the South Hadley Falls side; in other dimensions 38 feet high, 15 feet thick five feet below the crest, and 34 feet wide at the base. The model and details of this remarkable work invite the attention of hydraulic engineers and others interested in the stability of a great water power. The old dam will remain in its place and, with the space intervening between the old and new soon filled with the drift of the river, will remain buried through the years. A short canal on the South Hadley Falls side of the river, connected with the pond through an opening in the bulkhead of the dam, conducts the power to two large paper mills and a gingham mill; but the remaining bulk of the river's flow is conducted to the Holyoke mills by an elaborate canal system into which it is admitted through thirteen gates operated by a water-wheel set at the foot of a tower rising from the end of the dam. The receiving canal, running southeast from the bulkhead of the dam, is 1,013 feet long, 140 feet wide at the bottom and 144 feet at the top, and is stonewalled on either side. Its eastern end opens into the first or upper level canal, which runs southwest a mile and a quarter in a straight line, at first as wide as the supply canal, but narrowing at the rate of one foot in a hundred feet, and ending with a width of 80 feet. Parallel with this canal, distant 400 feet east and 20 feet lower, runs the second level canal, which receives the waters of the former after
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