THE PANAMA CANAL 



By Colonel George W. Goe 



Panam 



thals, Chief Engineer of the 

 a Canal 



IT is not possible in the time at our 

 disposal to enter upon a description 

 of the explorations and investiga- 

 tions which were made of various routes 

 proposed for a canal joining the two 

 oceans, nor can an account be taken of 

 the considerations which resulted in the 

 United States finally adopting the Pan- 

 ama route. Suffice it to say that under 

 the Spooner Act, approved June 28, 

 1902, the President of the United States 

 secured the necessary concession from 

 the Republic of Panama, purchased the 

 rights and property of the New French 

 Canal Company, and undertook the con- 

 struction of the canal on May 4, 1904. 



The Isthmus of Panama runs nearly 

 east and west, and the canal traverses, it 

 from Colon on the north to Panama on 

 the south, in a general direction from 

 northwest to southeast, the Pacific termi- 

 nus being 22 miles east of the Atlantic 

 entrance. 



TORRENTIAL FLOODS OE THE CHAGRES 

 RIVER 



The greatest difficulty of the Panama 

 route is the control or disposition of the 

 Chagres River and its tributaries. The 

 Chagres River rises in the San Bias 

 Mountains and drains a basin of 1,320 

 square miles, about half of which is 

 above the mouth of the Obispo River. 

 Its course is generally parallel to the 

 Caribbean coast line so far as the mouth 

 of the Obispo, where it turns almost at 

 right angles to the westward, pursuing 

 this general course to Tabernilla, whence 

 it traverses a tortuous channel in a gen- 

 eral northwesterly direction and enters 

 the Caribbean Sea to the west of Limon 

 Bay. 



The general elevation of the valley is 

 but little above sea-level to Bohio, where 

 the low-water surface of the Chagres is 

 one foot above mean tide. At the mouth 



of the Obispo, 13 miles from Bohio, the 

 low-water surface is 48 feet above, and 

 at Alhajuela, 11 miles farther, it is 95 

 feet above the same datum. Above Bo- 

 hio the Chagres Valley is undulating, the 

 hills becoming higher and steeper as the 

 river is ascended, causing very rapid 

 run-off of the rains, amounting to 100 

 inches and over in eight or nine months, 

 the average duration of the wet season. 



The maximum observed rainfall is 

 5.86 inches in one hour ; the greatest 

 recorded change in the river at Gamboa 

 is a rise of 25.6 feet in 24 hours. Its 

 discharge at the beginning of the rise 

 was 8,200 cubic feet per second, increas- 

 ing to 90,000 cubic feet per second at the 

 peak of the flood. The excessive rain- 

 fall and precipitous character of the hills 

 enclosing the valley make it a torrential 

 stream. The bars formed during floods 

 differ materially, and are of sand, gravel, 

 pebbles, and rounded stones three inches 

 to six inches in diameter. The sand and 

 clay deposits are useful in giving suitable 

 material for the impervious portion of 

 the dams, while the gravel beds furnish 

 ballast for the railroad and for other 

 purposes. 



The Chagres River has 26 tributaries 

 between Bas Obispo and Gatun, the 

 largest of which are the Gatun and Trini- 

 dad rivers, the former entering from the 

 -east with a drainage basin of about 160 

 square miles, and the latter from the 

 west, draining an area of about 390 

 square miles. Each rises in the same 

 character of country as the Chagres, and 

 though with smaller drainage areas, they 

 are of the same torrential character and 

 must be reckoned with in the general 

 question of the control of the Chagres 

 and its tributaries. 



Various methods for the disposition 

 or control of the Chagres have received 

 consideration. The first French com- 



An address to the National Geographic Society, February 10, 191 1. 



