1909] 0)1 the Americans and the Panama Canal. 699 



firm ground. The principal trouble seems to have been that the 

 clay moulded itself in the buckets and refused to drop off, thus 

 requiring endless patience, time and labour. 



A most perfect system of hauling materials from the cut is in 

 operation, and the handling of the dirt on the dumps is carried on 

 without loss of time. An excellent drainage system has been 

 perfected so that the rainy season causes no delay in the excavation. 



The greater width of the canal adopted by the Americans neces- 

 sitated the establishment of diversion channels further away from the 

 cut than those dug by the French. " The Obispo " diversion, on 

 the East side, drains a region of over 9 square miles. On the West 

 " the Camacho " drains Q^ square miles. The Camacho diversion, 

 4 miles long, was completed in 1908. Each takes the run-off from 

 tlie summit of the divide to the Chagres River. 



The French diversion channel for the Camacho River (on the 

 west side) has been utilised. A new channel riveted with stone has 

 been cut where it runs through Whitehouse yard ; the French tunnel 

 through the hill at Bas Obispo has been cleared and a dam constructed 

 across the Obispo River. The principal streams diverted by the 

 Camacho Diversion were the Camacho, the San Juan, and the Man- 

 dinga. 



The Chagres River has its sources in the mountains of Darien, 

 and flows in a S.W. direction as far as Bas Obispo, where, describing 

 a sharp turn, its waters proceed in a N.W. direction until they reach 

 Limon Bay in the Caribbean Sea. The line of the Canal follows in 

 a general direction, but not in its very tortuous channel, the direction 

 of the Chagres, in that section which will eventually be the Gatun 

 Lake, between Gatun and Bas Obispo. At Bas Obispo the hills of 

 the Continental Divide are encountered, and advantage has been 

 taken of the natural depression forming the Obispo River valley. 

 The Obispo rises at Gold Hill, a high point on the Culebra elevation, 

 and descends northwards into the Chagres river. The two rivers 

 meet at Bas Obispo. 



Where the Culebra Cut begins, exactly at Bas Obispo, low water 

 in the River Chagres is about 43 feet above mean sea-level. Ki 

 high water, or during floods, the level is 70 feet above mean sea-level. 



The Canal bottom through the Cut is to be at an elevation of 

 40 feet above sea-level, or, in other words, 3 feet lower than the 

 present level of the river at low water and some 30 feet lower than at 

 high water. During construction a careful drainage of the Cut when 

 the level of the bottom is brought below the lowest level of the river 

 is therefore imperative. 



The largest recorded flow of water in the rainy season was that 

 of September 21, 1894, when, according to French records, the 

 Upper Obispo discharged 36,995,000 cubic feet of water in 48 hours. 

 The discharge at the point where the stream crosses the Culebra Cut 

 was calculated at 6000 cubic feet per second. 



