Progress With the Panama Canal.
It is confidently stated that a firm foundation will be found for the Gatun dam; but engineering work of a difficult nature will be needed to shut off (what has hitherto been denied, but is now admitted by the Isthmian Canal Commission) the underground flow of water. The borings for the foundation of the locks have been extended 50 ft. below the level, on which the walls will be built. These borings disclosed the underground flow of water through the sandstone, the source of supply being apparently ground-water from the hills to the southeast at a considerably higher elevation than the lock site. It is intended to prevent access of this water to the foundation by means of curtain-walls connected with the underlying impervious stratum of argillaceous sandstone. The work itself is strong enough to bear any loads that may be laid upon it, and the principal water-bearing mediums are the fissures through the various strata, which allow the passage of water; this flow will be cut off, as in the case of the locks, by means of curtain-walls properly constructed and connected with the impervious layer underlying the soft rock. What seepage there is occurs in the top stratum and, though it is small, it is proposed to cut it off by sbeet-piling projecting up into the core of the drm and down into the impervious layer, which is sufficiently strong to support the proposed structure.