262 POPULAR SCIENCE MONTHLY. 



wind enough to take them out of Panama Bay are so serious as to 

 constitute a material objection to the location for a ship canal on the 

 Panama route. This difficulty undoubtedly exists at times, but the 

 simple fact is to be remembered that Panama was a port for sailing 

 ships for more than two hundred years before a steamship was known. 

 The harbor of Panama, as it now exists, is a large area of water at the 

 extreme northern limit of the bay, immediately adjacent to the City 

 of Panama, protected from the south by the three islands of Perico, 

 Naos and Culebra. It has been called a roadstead. There is good 

 anchorage for heavy draft ships, but for the most part the water is 

 shallow. With the commission's requirement of a minimum depth 

 of water of 35 feet, a channel about four miles long from the 

 mouth of the Eio Grande to the six-fathom line in Panama Bay must 

 be excavated. This channel would have a bottom width of 200 feet 

 with side slopes of one on three where the material is soft. Consider- 

 able rock would have to be excavated in this channel. At 4.41 miles 

 from the six fathom line is located a wharf at the point called La Boca. 

 A branch of the Panama Eailroad Company runs to this wharf, and at 

 the present time deep draft ships lie up alongside of it and 

 take on and discharge cargo, as do the trains of the Panama Eailroad 

 Company. This wharf is a steel framed structure, founded upon 

 steel cylinders, carried down to bedrock by the pneumatic process. Its 

 cost was about $1,284,000. The total cost of this excavated channel, 

 leading from Panama Harbor to the pier at La Boca, is estimated by the 

 commission at $1,464,513. As the harbor at Panama is considered 

 an open roadstead, it requires no estimate for annual cost of mainte- 

 nance. 



Starting from the harbor of Colon the prism of the canal is ex- 

 cavated through the low and for most part marshy ground to the little 

 village called Bohio. The prism would cut the Chagres Eiver at a 

 number of points, and would require a diversion channel from that river 

 for a distance of about five miles on the westerly side of the canal. 

 Levees or protective embankments would also be required on the same 

 side of the canal between Bohio and Gatun, the Chagres Eiver leaving 

 the canal line at the latter point on its way to the sea. 



The principal engineering feature of the entire route is found at 

 Bohio ; it is the great dam across the Chagres Eiver at that point, form- 

 ing Lake Bohio, the summit level of the canal. The new Panama 

 Canal Company located this dam at a point about seventeen miles 

 from Colon, and designed to make it an earth structure suitably paved 

 on its faces, but without any other masonry feature. Some borings 

 had been made along the site and test pits were also dug by the French 

 engineers. It was the conviction of the Isthmian Canal Commission, 

 however, that the character of the proposed dam might be affected by 



