wise beautifying the resort, which is visited annually by approximately 100,000 people from many parts of the world, who go there for rest, recreation and treatment. There are twenty-four wellequipped bath houses connected with the various springs. There is naturally much curiosity on the part of visitors to Hot Springs regarding the cause of the high temperature of the waters. In the Yellowstone National Park, where hot waters abound, the activity of igneous agencies offers a ready answer to such questions, but in Arkansas, where nearly all the rocks to be seen are of sedimentary origin, there is no evidence of recent volcanic activity, and such an explanation of temperature is not, therefore, so readily accepted. A. H. Purdue, State Geologist, 1907-1911, made a study of the source of heat in the waters of Hot Springs in 1909 with the following conclusions: The topography, stratigraphy and structure of the vicinity of Hot Springs indicate that the surface collecting area of the water is located not far from the springs. The water which originally falls in rainfall collects in the overturned, anticlinal valley between Sugarloaf and North Mountain and seeps down through the earth to issue forth in a spring at the lower level. The level of the surface at this anticlinal valley is higher than the level of the emergence of the springs. The exact location of the springs is attributed to the southwestern plunge of the Hot Springs anticline. The considerable thickness of the Big Fork chert, its much fractured nature, and the thin layers of which it is composed, all combine to make it a water-bearing formation of unusual importance. The areas of igneous rock at Potash Sulphur spring, Magnet Cove, and other places, force the suggestion upon one that the waters of the springs owe their temperature to contact with hot rocks or the vapor from such in some part of their underground course. The fact that hot springs within the Ouachita area are rare (a spring at Caddo Gap, issuing from the novaculite, has a temperature of from 98 to 100 degrees Fahrenheit), though there are scores of cold springs issuing from the same formations and under about the same geological relations, give this suggestion great weight; but inasmuch as some of the springs have been found to be radio-active, there is the alternative suggestion that atomic decomposition in igneous rocks (which many have lost their magmatic heat) is the source of the high temperature of the water. The analyses of the waters of the hot springs appear to warrant the following conclusions: 1. The waters of the hot springs are very pure. On an average the several spring waters contain 12.94 grains of material in solution to the gallon. Of this material nearly 60 per cent is carbonate of lime, over 21 per cent is silica, 9 per cent is carbonate of magnesia, while the remainder is chiefly chloride of sodium (common salt), sulphate of soda (Glauber's salt), and sulphate of potash. 2. There is but little difference in the composition of the waters of the various springs. 3. It has been demonstrated that the waters have definite therapeutic properties. 4. The waters may be piped without much loss of heat and without seriously injuring their medicinal value. +Temperature and Flow of the Hot Springs-Continued U. S. Senate Document No. 282, "Report on an Analysis of the Waters of the Hot Constituents (Hypothetical Combination) 423+24. Excluding the two cold springs 44 and 45. *Resume of Analyses of the Waters of the Hot Springs of Arkansas (In grains per United States gallon) 531+33. 25 .22 .34 .26 .25 .19 .27 .25 Sulphate of Soda (Na,SO,) Total Total solid material in solu- Temperature in de- Average temperature, 136.02°F. .06 .06 .06 .07 .02 .02 .07 .08 .05 11.62 12.13 11.97 13.07 11.46 11.22 11.73 11.75 11.88 13.70 13.12 12.07 12.94 12.83 13.12 13.47 13.06 12.94 3.81 4.17 4.07 3.63 4.57 5.12 5.66 5.76 4.71 134.78 144.68 139.28 146.48 139.28 115.88 142.90 124.88 136.19 Total solid material in solution, dried at 230°-239°F. (110°-115°C.), 13.03 grains per U. S. gallon. Carbonic acid (CO2), free and for bicarbonates, 4.60 grains per U. S. Gallon. "Mineral Waters," by J. C. Branner, "Annual Report of the Arkansas Geological Survey for 1891, Vol. I. Solids in Solution in Arkansas Springs *To give some idea of the comparative amount of solids in solution in the hot springs waters the total solids of several of the well known waters of the State as determined by the Geological Survey are given below: 7 to over 60 Arkansas River water at Little Rock (filtered) "Mineral Waters," by J. C. Branner.-Annual Report of the Arkansas Geological Survey for 1891, Vol. I. List of Arkansas Mineral Springs *The following is a partial list of the springs in Arkansas: Armstrong Spring, White County. Blalock Spring, Polk County. Stone County. Diamond Spring, Benton County. Frisco Spring, Benton County. Grandma Chase's Springs, Garland Griffin Spring, White County. Happy Hollow Springs, Garland Homing Hill Springs, Pulaski Hot Springs, Garland County. (For Lithia Spring, Baxter County. |