THE PANAMA CANAL 



343 



merits of the lock versus sea-level canal 

 must rest upon the ease and safety of 

 navigation offered by the two types. 



the: sea-level type makes no provision 



POR CONTROLLING THE PLOODS OP 

 THE CHAGRES RIVER 



In the sea-level type offered in lieu of 

 the lock type already described, the 

 Chagres River is controlled by a masonry 

 dam across the valley at Gamboa 4,500 

 feet long, 750 feet of which is subject to 

 a pressure due to a head of 170 feet 

 during the extreme flood stages of the 

 river. Proper sluice gates are proposed 

 for discharging the river into the canal. 

 The difference in tides is overcome by 

 means of a lock on the Pacific side in the 

 vicinity of Sosa Hill. While provisions 

 are made for damming or diverting some 

 of the streams that would otherwise enter 

 the canal prism, not less than 22 flow 

 directly into the canal, with no provision 

 to control the currents or check the de- 

 posits of material carried by them during 

 flood stages. 



The prism of the canal is to have a bot- 

 tom width of 150 feet through the earth 

 sections, or for nearly one-half its length, 

 and a 200-foot bottom width through the 

 rock sections. Nineteen miles of the 

 length are made of curves, so that the 

 proposed sea-level canal is not a wide, 

 straight, and open channel, connecting 

 the two oceans, but a narrow, tortuous 

 ditch, with varying currents of unknown 

 strength, impeded by a lock, and threat- 

 ened by a dam resisting a pressure due to 

 a head twice as great as that at Gatun. 



To be sure, the partisans of the sea- 

 level type are now proposing to eliminate 

 both the Gamboa dam and the tidal lock 

 by making the channel so wide as to re- 

 duce the currents that result from the dis- 

 charge of the Chagres and the difference 

 in tides, but fail to explain how they pur- 

 pose to control or divert the Chagres, the 

 bed of which will be 50 feet above the 

 water surface of the canal at the junc- 

 ture. As data is not available for pre- 

 paring accurate estimates for even such a 

 sea-level type as was originally offered, 

 neither they nor any one else can offer 



any figures as to time and cost for the 

 construction of such a canal as they now 

 advocate. 



In any comparison, therefore, we must 

 confine our attention to the lock type as 

 now building and a sea-level canal as 

 offered by the board of engineers and 

 not by the idealist. 



POR OUR BATTLESHIPS AND SHIPS OP COM- 

 MERCE THE LOCK TYPE IS QUICKER 

 AND SAPER 



So far as the two prisms are concerned, 

 for ease and safety of navigation the lock 

 type is better because of the greater 

 widths of channels, fewer and easier 

 curves, and freedom from objectionable 

 and troublesome currents, both from the 

 Chagres and its tributaries. This must 

 be admitted by all, but the exponents of 

 the sea-level type concentrate their atten- 

 tion on the obstructions and dangers that 

 the locks constitute in the lock type, and 

 also on the dangers that will result from 

 the failure of the Gatun dam, forgetting 

 that at least equally great disaster must 

 follow the failure of the Gamboa dam. 

 The lock in the sea-level canal is not men- 

 tioned, probably because the danger is 

 not so great, since there is but one. 



Experience shows that the risks to 

 ships in narrow waterways are material 

 and important. In such a channel as the 

 original Suez Canal the delays and losses 

 to commerce were great, and the danger 

 to ships considerable ; although the benefit 

 of the widening is striking, this is true 

 even now. 



It is well known that the narrow chan- 

 nels connecting the Great Lakes have 

 been obstructed repeatedly by vessels 

 aground or wrecked in such a manner as 

 to block traffic. Even in the entrances to 

 our seaports there is a frequency of acci- 

 dents which illustrate the difficulties en- 

 countered in navigating narrow and tor- 

 tuous channels. 



Accidents in locks have been relatively 

 few, and none of a serious nature have 

 occurred at the Saint Marys Falls Canal 

 during fifty-four years of its use. The 

 risks to ships in such a narrow waterway 

 as proposed for the sea-level canal at 



