Page:Popular Science Monthly Volume 48.djvu/230

218 and the sixteenth wells are each eighteen metres deep, while the sixth, at the summit of the hill, is sixty-six metres deep.

Sauvage concluded that the tunnel had been left unfinished, which later examinations have fully proved. The fact that the first and second wells contain water indicates that it had been completed on the lake side for at least five hundred metres. The exploration in 1882 of the thirteenth well, whose orifice is at an elevation of 107·68 metres, discovered, at a depth of 28·30 metres, a horizontal gallery, 1·60 metre wide and 1·65 metre in the axis.



cut in each direction about six metres. At 2·15 metres below this was found a second gallery of the same section, cut in the same direction, and the shaft was excavated 270 metres farther down, probably for use as a drainage well, ending in a level bottom, its total depth being 36·50 metres. The fourteenth, fifteenth, and sixteenth wells, at decreasing altitudes, show a similar interior disposition, save that in the fourteenth the gallery has been but slightly advanced and there is no drainage well. In the fifteenth shaft, which has a total depth of 78·93 metres, the upper gallery is cut to a depth of five metres on the west and two metres on the east, and the lower one 10·30 metres on the west and 10·70 on the east, while the well is 4·70 metres deep. In the sixteenth well the