Page:Popular Science Monthly Volume 19.djvu/42

32 With the exception of the High Rock, nothing of especial interest has attended the efforts to secure any of these waters. This spring takes its name from the pyramidal formation, which is composed of tufa, formed by the gradual deposition of the calcareous and other mineral matter that has been precipitated from the water as it flowed from its outlet. Up to 1865 there had never been any attempt made to secure the flow by artificial means, but in that year the proprietors conceived the idea of removing the tufaceous rock, and by excavating to a sufficient depth obtain water of better quality and in greater abundance. In accordance with this design, the rock, which measured four feet in height and about eight in diameter at the base, was carefully removed from its original position, and the work was commenced. After having penetrated the superficial deposits, a layer of seven feet of commingled muck and tufa, superimposed upon two feet of tufa, was encountered. Immediately below this the workmen found the trunk of a Pinus alba, which measured about a foot in diameter, and which was in a fair state of preservation. The next stratum was tufa, three feet in thickness, below which was two feet of drift. Lying immediately below this, a glacial clay bed, eighteen inches in thickness, was found, upon the surface of which an ancient hearth was discovered, composed of a semicircular row of stones, partially surrounding a quantity of charcoal, over which an incrustation of tufa was deposited. This circumstance was one of particular interest to students of archæology, as it involved the solution of a vexed question regarding the time at which the fire was kindled, as well as the character of the race, and the manners and customs of those by whom it was lighted. Inasmuch as the relic was discovered below the drift formation, its builders might have lived at a period anterior to that of the mound-builders of the Mississippi Valley. After having penetrated to the calciferous sand-rock, the tube was adjusted and the High Rock replaced, from the apex of which the water has continued to flow.

At the present time there are probably forty mineral springs within the limits of this town. Thirty of this number have received names, and twenty-two have been analyzed. The table appended shows the proportions of the various constituents contained in a United States gallon of two hundred and thirty-one cubic inches.

To a certain extent the classification of mineral waters is an arbitrary one, different authorities following their own inclinations in their arrangement. By many they are divided into four classes, as follows:

1. Gaseous or acidulous: those in which carbonic-acid gas is a predominating constituent.

2. Saline, or those in which various salts are held in solution, in addition to the gas.