The tank was about sixty feet in depth, and perhaps a mile in length, with half that breadth.

Its sides and bottom-were lined with the usual concrete.

Our guide informed me that in many cases tanks were covered with the crystal employed for doors and windows; but in the-pure air of these hills such a precaution was thought unnecessary, as it would have been exceedingly costly.

The water itself was of wonderful purity, so clear that the smallest object at the bottom was visible where the Sun, still high in the heavens, shone directly upon the surface.

But this purity would by no means satisfy the standard of Martial sanitary science.