APPENDIX P.

 TRANSFORMATION OF A LOCK CANAL INTO A SEA-LEVEL CANAL.
 REPORT OF THE COMMITTEE ON LOCK-CANAL.



 The Lock-Canal Committee, in accordance with requests made at the meeting of the Board held on Tuesday, November 7, herewith respectfully submits a report upon the practicability and cost of developing a sea-level canal from a lock canal.
 It had before it the resolution upon this subject adopted by the Board at its sixth meeting, which is as follows:
 Resolved, That it is desirable that studies shall be made of the practicability of developing a sea-level canal from any project which primarily involves a lock canal.
 It had also before it the remarks of the President of the United States upon this subject, dated September 11, 1905, which are as follows:
 I desire also to know whether, if you recommend a high-level multilock canal, it will be possible after it is completed to turn it into, or to substitute for it, in time, a sea-level canal, without interrupting the traffic upon it.
 Our studies of this subject led us to the conclusion that the President's request may be answered in the affirmative, as we believe it to be possible to turn a lock canal into a sea-level canal without interrupting the traffic upon it. In order to do the work in an economical manner, however, it might be advisable to use methods which would sometimes delay ships passing through the canal.
 The committee does not regard the depression of a lock canal to sea level as an easy task or one for which a trustworthy estimate of cost could be made at the present tinie. It evidently involves the excavation of immense quantities of rock and earth, much of it at depths considerably exceeding 40 feet below the surface of the water. The Board,- having in view the removal of rock at depths less than 40 feet, has adopted as the price for excavating rock under water $2.50 per cubic yard, while for rock excavated "in the dry it has adopted $1 and $1.15 per cubic yard, except in the Culebra cut, where for all classes of materials above elevation +10 a price of 80 cents per cubic yard, and for all classes of materials below elevation +10 a price of $1.25 per cubic yard has been adopted. For the dredging of earth from the canal a price of 25 cents per cubic yard was adopted as against 40 cents per cubic yard for earth in the dry.
 As rock is the predominating material to be excavated in depressing the canal from a lock level, it is obvious from the unit prices adopted that a sea-level canal obtained by first building a lock canal would cost very much more than a sea-level canal constructed by a direct process, and we believe that if a sea-level canal is necessary in the near future it should be built directly without first building a lock canal.
 If the transformation should be delayed until the traffic became very great, the committee believes a wider channel than that proposed by the Sea-Level Canal Committee would be required, and accordingly submits two estimates of the cost of such transformation, one to a 411