tion have been necessitated by slides, and there are at present three million cubic yards of material in motion. A great deal of expense and trouble has been occasioned by these disturbances, but they are not to be considered as sources of future danger. It is highly improbable that any serious movements of the earth will take place after the Canal is completed. The locks are the most essential and at the same time the most hazardous features of the waterway. It is believed, however, that the safety devices which will be installed and the precautions which will be enforced may be depended upon to prevent any serious mishaps. Experience proves that the great majority of accidents that occur in the operation of locks are due to mistaken signals. In the Panama Canal no vessel will be permitted to go through a lock under its own steam. Electricity, applied through locomotives operating on the walls, will be employed to tow ships through the locks. Protective chains, guard gates, caissons, emergency dams, and other contrivances will be available to minimize the effects of any mischance. Not content with these provisions for safety, the Canal administration is seeking authority from Congress to place a pilot on board every vessel entering the Canal, Four The lock on the right is nearly filled for an upward lockage. electric locomotives are shown securely holding a 10,000-ton ship, and ready to tow it out of the lock, so soon as the upper gates are opened. At the entrance to the lock on the left is shown a caisson in position and acting as a barrier between the high level above and the low level below the lock. On the right is shown an emergency dam in its normal position when not in use and on the left the other dam is shown swung in position across the lock with the wicket girder down in readiness to support the wickets or gates which complete the barrier. with control over its navigation throughout the passage. Such a measure would be approved by owners and masters of merchant ships, who would find in it relief from responsibility and ready indemnity for any damages that might be incurred during transit. On the other hand, naval officers will certainly oppose the measure as an infringement upon their dignity and a reflection upon their capability. The locks will be filled and emptied through a system of culverts. One culvert, two hundred CROSS SECTION OF LOCK CHAMBER AND WALLS OF LOCKS E-These culverts run under the lock floor G-Culvert in sidewalls H-Lateral culverts and fifty-four square feet in area of cross section, about the area of the Hudson River tunnels of the Pennsylvania Railroad, extends the entire length of each of the middle and side walls, and from each of these main culverts there are several smaller ones which extend under the lock chambers and connect with them through holes in their floors. To fill a lock the valves at the upper end are opened and the lower valves closed. The water flows from |