THE PANAMA CANAL 



337 



this plan the Board of Consulting Engi- 

 neers concluded that — ■ 



"After a full and careful consideration of all 

 the features of Mr Bunau-Varilla's plan, the 

 board is of the opinion that it should not be 

 adopted for the Panama Canal for the follow- 

 ing reasons : 



"i. The construction of the large locks re- 

 quired under the present law and necessary for 

 the accommodation of the traffic seeking the 

 canal after its completion makes it quite im- 

 possible to complete the preliminary lock canal 

 even nearly within the period stated. 



"2. The excessive cost of transformation ad- 

 ded to the loss of costly locks and other appur- 

 tenant structures required by the preliminary 

 lock canal. 



"3. If the lock canal is likely to be retained 

 for many years, it should be made for the most 

 efficient service, and not be encumbered with 

 modifications in lock construction which would 

 prove inconvenient in use." 



(4) A plan proposed by Maj. Cassius 

 E. Gillette, a lock canal with a summit 

 level 100 feet above mean tide by the 

 construction of a dam across the Chagres 

 Valley at Gatun. 



No sea-level plan was submitted for 

 consideration, so that the board outlined 

 a general plan of its own, and for pur- 

 poses of comparison adopted as the lock 

 type a 60-foot summit level canal. Two 

 levels were used ; the summit level was 

 carried by an earth dam at Bohio, and 

 the intermediate level by an earth dam 

 at Gatun, each dam sustaining a head of 

 30 feet. It is to be noted that no diffi- 

 culties were anticipated in the construc- 

 tion of these dams, and there was no 

 dread or fear of the foundations. 



As the result of its deliberations, the 

 board submitted a majority report and 

 a minority report signed by five of its 

 members, the former ad\ocating a sea- 

 level canal and the latter a lock canal, 

 with the summit level 85 feet above mean 

 tide. 



THE LOCK TYPE IS ADOPTED 



The Isthmian Canal Commission, 

 with one dissenting voice, recommended 

 to the President the adoption of the lock 

 type recommended by the minority, 

 which was also strongly advocated by 

 the then chief engineer, Mr John F. Ste- 

 vens. The President, in the message to 



Congress dated February 19, 1906, 

 stated : 



''The law now on our statute books seems to 

 contemplate a lock canal. In my judgment a 

 lock canal, as herein recommended, is advisable. 

 If the Congress directs that a sea-level canal be 

 constructed its direction will, of course, be 

 carried out ; otherwise the canal will be built 

 on substantially the plan for a lock canal out- 

 lined in the accompanying papers, such changes 

 being made, of course, as may be found actually 

 necessary, including possibly the change rec- 

 ommended by the Secretary of War as to the 

 site of the dam on the Pacific side." 



On June 29, 1906, Congress provided 

 that a lock type of canal be constructed 

 across the Isthmus of Panama, of the 

 general type proposed by the minority 

 of the Board of Consulting Engineers, 

 and work has continued along these 

 lines. As originally proposed, the plan 

 consisted of a practically straight chan- 

 nel 500 feet wide, 41 feet deep from deep 

 water in the Caribbean to Gatun, where 

 an ascent to the 85-foot level was made 

 by three locks in flight. The level is 

 maintained by a dam approximately 

 7,700 feet long, one-half mile wide at 

 the base, 100 feet wide at the top, con- 

 structed to 135 feet above mean tide. 

 The lake formed by this dam, 171 square 

 miles in extent, carried navigation to 

 Pedro Miguel, where a lock of 30 feet 

 lift carried the vessel down to a lake 55 

 feet above mean tide, extending to Sosa 

 Hill, where two locks overcame the dif- 

 ference of level between the lake surface 

 and the Pacific. Nineteen and eight- 

 hundredths miles of the distance from 

 Gatun to Sosa Hill had a channel 1,000 

 feet at the bottom, a minimum channel 

 for /± l / 2 miles through Culebra of 200 

 feet at the bottom. The balance of the 

 distance varied in width to 800 feet, the 

 larger portion of the entire canal being 

 not less than 500 feet. The depth of 

 water was fixed at 45 feet. The lake as- 

 sured a perfect control of the Chagres 

 River. 



IMPROVEMENTS IN THE ORIGINAL PEANS- 



Certain changes have been made in 

 the original project, the most important 

 being the withdrawal of the locks from 



