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Zeutschel OS7000, 400 dpi, 8 bit, 10,992,464 bytesThe depth to bed rock at the Buttes having early been proved so great as to demonstrate that the dam would necessarily be a very costly one, if feasible at all, it was widely decided, during the progress of the borings at that point that the scope of the investigation should be widened to cover all other possibilities of water storage on the river above the Buttes, in the hope of finding alternative sites where the purpose sought could be effected more safely, more certainly, and at less cost. Trial borings were made at the Dikes, 4 miles above; at Riverside, 12 miles above; and at San Carlos, 60 miles above, while surveys were made of a site still further up the river at Duncan, near line dividing Arizona and New Mexico. Fortunately the appropriation was sufficient, with rigid economy, to permit all of this work and obtain such results that it may be fairly said that the subject of water storage on the Gila is practically exhausted, and all feasible alternatives to the Buttes site are definitely known.The study of the water supply involved a comprehensive examination and measurement of the Gila River and all of its main tributaries; an enumeration and measurement of the various canals and ditches diverting water from these streams above the Buttes, and an investigation of the areas of land thus irrigated; a study of the intricate and interesting phenomena attending the return of water to the river from the irrigated fields by seepage; an investigation into the loss of water by evaporation, and the compilation of rainfall statistics from all of the stations where precipitation has been observed and recorded on or near the watershed of the Gila. THe feasibility of establishing reservoirs upon the stream has necessitated a detailed contour survey of all the projected dam and reservoir sites, a computation of their area and capacity, and the area of the watershed tributary to them; a consideration and determination of the volume of silt carried by the river and a computation of its probable total volume per annum, together with a compilation of all the measurements of the flow of the river at all points and times of which there is record. The study of the cost and feasibility of the erection of dams of the types considered has necessitated the examination and test of the various building materials available; analyisis and tests of strength of the rocks to determine their suitability for foundations; quarry tests of the neighboring cliffs to ascertain the behavior of the rocks when thrown down in large masses, and its quality beneath the surface exposure; investigations of limestone clays and fuel to determine the feasibility of manufacturing hydraulic lime, natural cement, artificial cement, and sand cement from imported Portland cement, in the endeavor to exhaust the possibilities in the way of overcoming the disadvantages of the remoteness of the sites from the seaboard, and thus reach the ultimate economy of construction. The successive steps taken in these various lines of investigation are treated at length in Mr. Lippincott's report. It must be concluded from this brief summary of the work accomplished that the entire investigation has been upon broad lines; that it has been thorough; and that its general scope, as determined by the engineers in charge, has been sufficiently comprehensive to secure all the collateral data necessary to form the basis for intelligent action upon the question of its entirety.THE VOLUME OF WATER TO BE STORED. One of the first matters to be considered in a report of the character called for by the act of Congress is as to the volume of water whic