692 3Ir. A. Henry Savage Landor [June 18, 



the base between lateral toes of piled rock. The two toes of rock 

 have already been completed over half the width of the valley. The 

 length of the dam will be Ih miles, its maximum height 115 feet. 



The material of the earth's crust in the Gatun region can be 

 roughly classified as sedimentary, metamorphic (merely limestone), 

 and igneous rocks, the first subdivided into conglomerate (a con- 

 solidated gravel) and sandstone. The igneous subdivisions are 

 trap (a basalt), lava flow, and ryolite, or fragmentary tufa and 

 volcanic ash. 



So far, the great question of Panama resolves itself into whether it 

 is preferable to build a sea-level or a lock canal. 



The strongest advocate of a sea-level canal — " The Straits of 

 Panama," as he calls it— is a most eminent French engineer, M. 

 Bunau-Varilla. He is a man of extensive experience in the construc- 

 tion of dams, harbour works, and railways. His life work has been 

 in connection with the Panama Canal. He has thrown his entire 

 heart and soul into studying the possibilities of constructing a 

 practical waterway across the Isthmus. 



I had a long conversation with M. Bunau-Varilla in Paris, and 

 was impressed by the genius of this man. What he says of locks and 

 sea-level canals is true. The Americans might do worse than ponder 

 over tlie statements made by ^I. Bunau-Varilla. 



There are certainly disadvantages in a lock canal which are not to 

 be found in a sea-level canal, such as the damage that may be done 

 to locks by a crippled ship, by unexpected explosions, by treacherous 

 hands, by submarine vessels, or by airships overhead ; by possible, if 

 perhaps not probable, volcanic commotions, or by the collapse of the 

 dam. It must be borne in mind that with the increase in the 

 dimensions of vessels, the margin which is to-day reckoned as ample, 

 for instance, in the construction of locks, may be found insufficient 

 in a few years to come. 



One should, on the other hand, not lose sight of the immense 

 economy of time which the constructioTi of a lock canal will afford. If 

 all goes well, a lock canal will, for the present, answer just as well 

 as a sea-level transcontinental waterway. Moreover, it can at any 

 time be transformed into a sea-level canal by dredging in the wet. 



Personally, I greatly admire M. Bunau-Varilla's highly scientific 

 prophecies, and fully recognize their wisdom. So do, I think, almost 

 all Americm officers on the Canal Zone. I am not certain whether 

 the Americans, hampered by their laws and restrictions on labour, 

 would be able to work the dredging operations at the low figure, 

 quoted by M. Bunau-Varilla. It must not be forgotten that it costs 

 an American four times what it would cost a European to do any- 

 thing. One could see, lying in the Canal Zone to rust and waste 

 several hundred tliousand dollars' worth of old French machinery 

 which, because of peculiar American regulations, could neither be 

 sold for old iron nor used. This could not happen in other countries. 



