340 



THE NATIONAL 



GEOGRAPHIC MAGAZINE 



vestigations have failed to disclose any. 

 The great mass of underlying materia! 

 is not sandy and gravelly deposits, as 

 was supposed, but a mixture of these 

 materials so firmly cemented together 

 with clay as to make the strata in which 

 they occur impervious to water. 



THE FOUNDATION OF THE DAM AND LOCKS 

 AT GATUN IS SATISFACTORY 



I venture the statement, without fear 

 of contradiction, that the site of no pub- 

 lic or private work of any kind has re- 

 ceived such a thorough and exhaustive 



§ examination and investigation as the 



< foundation of the dam and locks at 

 £ Gatun. There is no longer a doubt con- 

 ^ cerning any of the underlying strata ; 

 % neither the impermeability nor the ability 

 ° of the foundations to bear the loads 'that 

 § will be brought upon them can be ques- 



< tioned if the data be carefully and im- 

 ^ partially examined. The investigations 

 % fail to disclose any water-bearing strata 

 2 or the existence of that underground 

 << stream with a discharge equal to the 

 2 Chagres River itself, which was recently 

 ^ asserted as a fact on the floor of the 



< Senate. 



0 In this connection the statement is also 



g made that the change in the location of 



^ the locks at the Pacific end was due to 



g our demonstrated inability to construct 



m the dams, and that as the foundation at 



5j Gatun is of the same material, it neces- 



2 sarily followed that the Gatun dam is 



w also impossible of accomplishment, 



g The majority of the Board of Consult- 



H ing Engineers in its report states that — 



m "The dam at La Boca, between San Juan 

 Point and the Sosa Hill, unless carried down 

 to bed rock at that location, would be placed 

 upon a far worse foundation than that pro- 

 posed at Gatun or Mindi. The La Boca site is 

 one covered by an ooze of mud or silt, with 

 some sandy material overlying the rock. . . . 

 Unless some feature equivalent to that of a 

 heavy masonry core characterized the design of 

 the clam at this point, or unless a resort be 

 made to dredging down to bed rock or near to 

 it, and refilling with suitable material, or an 

 earth dam at this location be made very mas- 

 sive, it would be in grave danger of being 

 pushed bodily out of place by the pressure due 

 to the head of water in the reservoir." 



We found the material in the founda- 



