Let us now inquire into the condition of the soil of the city. We find that the general direction of the water trend is from northeast to southwest; that the water level in the wells near the Atlas works is thirty-five feet above the river level at the city water works; and that the waterfall is from fifteen to eighteen feet per mile. The formation of the ground beneath the city is attributed by geologists to the glacial drift of pre-historic times. From seventy to ninety feet below the surface the earth is built up of alternate beds of sand gravel, and clay, and go to show that at some remote period running water with its leveling and transforming power, aided by the corroding force of the air, contributed largely to the geological formation which we find to-day. After obtaining the distances through these various strata in the different parts of the city, an average is calculated in the following order: Loam, three to four feet; sand and gravel, thirty to forty feet; blue compact clay (hard-pan), twelve to eighteen feet; sand and gravel, five to ten feet; soft clay, one to five feet; and blue gravel and boulders to Devonian limestone, thirty-five to fifty feet. The first stratum of clay is very hard and tough, and for that reason is called “hard-pan.” It has an inclination from the northeast to the southwest of about thirty feet to the mile. The further north and east of White river, the less distance it is to bed rock. Occasionally below the “hard-pan” is found a small drift of soft clay, but this is not usual and does not extend very far in area; often in moving ten feet it is missed. The first seam of water is usually reached at a depth of seventeen to twenty-five feet; the second seam at fifty to sixty-five feet; and the third seam at seventy to ninety feet. These various strata of water are all what is called “hard water.” Prof. E. T. Cox states that “the first seam contains the largest amount of mineral water, principally calcium carbonate, magnesium carbonate, chlorides and ferrous sulphate. The amount of chlorine is so large, that its presence is due in a great measure to sewage contaminations. The second seam of water contains but little chlorides, but has about the same amount of calcic and magnesic carbonates as the first. It is a good potable water when properly protected from contaminations from the upper seam. The third seam of water is also a hard water, that is, its salts will decompose a portion of soap and form a curd; but it contains less carbonates and more sulphates of the alkaline earths, lime and magnesia.” Inasmuch as the object of this paper, is to show to what extent the soil and water of Indianapolis are affected by pollution and the influence such pollution has on health, it is proper to state as nearly as possible, the sources from which the contamination arises. By the assistance of the former civil engineer of the city, the following estimate was made: