The majority of the board declared in favour of a sea-level canal as the only plan "giving reasonable assurance of safe and unin terrupted navigation"; while the minority recommended a lock canal, rising to an elevation of 85 ft. above mean sea-level, on the grounds that it would cost about $100,000,000 less than the pro posed sea-level canal, that it could be built in much less time, that it would afford a better navigation, that it would be adequate for all its uses for a longer time, and that it could be enlarged if need should arise with greater facility and less cost. These conflicting reports were then submitted to the Isthmian Canal Commission for consideration, with the result that on Feb. 5, it reported, one member only dissenting, in favour of the lock canal recommended by the minority of the board of consulting engineers. Finally this plan was adopted by Congress in June 1906.
Tenders of private contractors proving unsatisfactory Presi dent Roosevelt decided that it would be best for the Government to continue the work, which was placed under the more imme diate control of the U.S.A. Corps of Engineers. At the same time the Isthmian Canal Commission was reorganized, Col. G. W. Goethals, of the Corps of Engineers, becoming engineer in chief and chairman on the resignation of J. F. Stevens (April 2, 1907). This commission was composed of f our army engineers, an army doctor, one navy engineer and one civilian. President Roosevelt, who was convinced that the best results could not be obtained through an executive body of seven members, issued an executive order in January 1908 placing supreme power in the hands of Col. Goethals, abolishing the commission as an executive body, and making its members, who were heads of departments, sub ordinate to him, giving Col. Goethals all civil, military and other powers in the canal zone, and this course was subsequently ap proved in the act of 1912 for the government and operation of the canal after its completion.
The construction period of the Panama canal covered about 10 years, but the actual work of construction was accomplished in about seven years; the first three years were devoted to preliminary preparation, during which time the thorough sani tation of the Canal Zone was accomplished, yellow fever banished, an operating plant assembled, the railways modernized, a work ing force gathered, living quarters erected and a food and water supply provided. The plans for the canal itself had yet to be worked out in detail when the third commission took charge. Important changes in the general plan of the canal made it neces sary to evolve an entirely new set of plans for lock and dam construction on the Pacific side and also for basal dimensions of the channel. The original plans provided for a total excavation of 95,000,000 cu.yd. and a total cost of $190,000,000 exclusive of $40,000,000 paid to the French Canal company, $10,000,000 paid to the Panama republic, and the cost of sanitation and civil administration. Changes made in 1908-09 increased the total excavation to 175,000,000 cu.yd. and the estimated cost to $375,210,000 inclusive of payments to the French Canal Company and the Republic of Panama. When the lock canal plan was adopted in 1906, it was estimated that nine years would be required for its completion, placing the date at Jan. 1, 1915. This date was accepted and the work was adjusted and prosecuted to this end. During the first five years under the Third Commis sion 75% of the entire excavation of the canal was accomplished. In spite of the fact that "slides" added more than 25% of the total excavations from Culebra cut, and were not taken into account in the estimated time or cost, the work was advanced to such a stage that the first ocean steamer was passed through on Aug. 3, 1914, and but for an unexpected slide which occurred on Oct. 14 of that year would have been completed in its entirety within the estimated time and below the estimated cost. When the canal was declared formally complete and open, a total of about 240,000,000 cu.yd. had been excavated and the total cost, exclusive of expenditures for naval and military defence, was only $366,650,000, of which $10,000,000 was for "slides" or breaks in the walls of the cut of which there were about 30 at different times.