248 Kansas Academy of Science. 



well, 500 feet distant, was reduced by two feet. The old tomb 

 spring was reduced one-third. 



"Having now the exact conditions in the formation, and knowing 

 the presence of the cemented dam around the hill, and its approxi- 

 mate width, we concluded to cut No. 2 tunnel to isolate the old 

 tomb in blue clay, just carrying the sand level in the very top of 

 the heading. The tunnel was driven in 125 feet. We encountered 

 small streams of water as we went along, and broke through the 

 limestone crust that lay between the blue clay and sand. Bore 

 holes were made upward, so that we could feel our way across the 

 iron dam. At 120 feet we commenced to get a good deal of water. 

 All proper precautions were taken when we should break through 

 under the dam. Sand-bags and grass were in readiness, and when, 

 at 125 feet, we went into water-bearing sand, it was successfully 

 held back and the water allowed to run out. The old-tomb 

 spring stopped, and the tunnel was allowed to stand, except that a 

 solid gravel filling was put in the heading in place of the grass and 

 sand. This tunnel is to be filled with gravel, except near the 

 mouth, where a cement wall, backed by a rammed blue-clay filling, 

 is to be used as a dam, to back the water, to be carried off in pipes 

 for further use. The water coming from the two tunnels is now 

 cencentrated into a cistern that had been constructed some years 

 ago, and is forced into tanks by hydraulic rams, from which Mount 

 Vernon gets its supply of water. The supply has been sufiicient 

 for all general use. The flow is 15,000 gallons per day now, from 

 both tunnels. No diminution can be detected in the flow of the 

 two tunnels. No sand is observed in catch-basins. Everything 

 seems to come to rest, 



"CONCLUSION. 



"The problem is successfully solved. The whole hillside affected 

 by the tunnels has dried out. No. 1 tunnel, left for observation, is 

 to be filled with gravel, so that a channel will be left that will never 

 close up. The theory regarding the dam formed around the brow 

 of the hill may be of interest, and seems to have been borne out by 

 facts. The iron in solution in the water was deposited probably in 

 the form of pyrite by coming in contact with the tree roots. This 

 was gradually changed to limonite. Old trees died out ( last slide 

 had two dead stumps of very old trees at its head), and gradually 

 in wet seasons the water dissolved the iron, and a break in the dam 

 occurred, and this caused a landslide. 



"A quite interesting thing has been observed recently, pointing 



