THE PANAMA CANAL 



177 



whereas the Gatun Dam was built with a 

 slope of about one in ten. The founda- 

 tion was simply spread, making the dam 

 about a third of a mile through at the 

 base, so that the underlying material 

 would carry the load. This underlying 

 material was compressed under the load 

 in some places as much as 15 feet. As 

 the load was gradually placed on it, the 

 material in the base became more and 

 more compact, until finally settlement has 

 practically ceased. 



Every two or three months borings 

 have been made through the material in 

 the dam itself, and that under it, for the 

 purpose of ascertaining any changes in 

 the character of such materials. This 

 data shows that the material, both in the 

 dam and under it, is continually becom- 

 ing more compact. It stands today, safely 

 carrying its full load, and tomorrow it 

 will be able to carry more. 



THE: JAMAICAN IS HARD TO KlfX 



The dam was built by constructing 

 trestles in both edges of it and from these 

 trestles making rock fills or "toes." When 

 these toes had reached a height of 60 

 feet on the south face and about 30 feet 

 on the north, dredges commenced to 

 pump an impermeable mixture of sand 

 and clay in between them. This central 

 core constitutes the real barrier to the 

 passage of water through the Gatun 

 Dam. 



As the hydraulic fill was built up the 

 rock fills were carried up, so as always to 

 constitute levees, holding the additional 

 hydraulic fill. A pipe-line dredge pumps 

 about 20 per cent solid material and 80 

 per cent water, so in building a dam in 

 this way it is necessary to provide some 

 means for draining off the surplus water. 



This was done where the dam joins the 

 hill, a 20-inch pipe being laid in a trench 

 on the rock and carried in to the lower 

 edge of the hydraulic fill. An elbow was 

 then placed on the end of the pipe, and as 

 the water and hydraulic fill rose other 

 sections were added to the elbow. A 

 cage was placed around the intake end of 

 this pipe to keep the drift away, and men 

 were sent occasionally to remove such 

 <irift from the pipe intake. 



At one time when water was running 



through this pipe under a 30-foot head, 

 three Jamaicans were removing drift and 

 one of them fell in the 20-inch pipe. The 

 other two tried to pull him out but could 

 not. They let him go and ran as quickly 

 as they could to the other end of the pipe. 

 The man traveling in the pipe reached the 

 end first, notwithstanding the fact that he 

 turned a corner at an angle of 90 degrees. 

 His ears were scratched a little ! 



There was a great deal of emulation 

 between the employees in the different 

 divisions. The part of the story so far 

 told is true, but Colonel Gorgas made the 

 addition that the man jumped up and 

 said that there wasn't anybody on the 

 Pacific Division who could do that. 



The spillway over which the surplus 

 waters of the Gatun Lake find their way 

 to the Atlantic Ocean is found on page 

 170. This is a picture of the spillway 

 when practically complete. 



The gates on top are 45 feet wide and 

 the lake will stand 16 feet deep against 

 them when no water is being wasted ; 

 consequently if one or more of the gates 

 is lifted water will flow between the piers 

 16 feet deep. These gates are raised and 

 lowered like a window-sash. These mov- 

 able gates constitute the regulating works, 

 by means of which the level of Gatun 

 Lake is controlled. 



"the: queen oe America" and the 

 luncheon party 



In the beginning but very little pro- 

 vision was made for quarters for families 

 of the canal employees. It soon became 

 evident that order could not be main- 

 tained, contentment prevail, and a per- 

 manent force kept unless the wives of the 

 men were there ; so the commission un- 

 dertook to build family quarters. 



It was announced in circulars, etc., that 

 employees would be provided with family 

 quarters within ten months after arrival 

 on the Isthmus. Not only all the mar- 

 ried men immediately applied for quar- 

 ters, but nearly every unmarried man on 

 the job applied. Family quarters carried 

 with it free light and fuel. 



Nearly every one of the young unmar- 

 ried men the first time they came back 

 from leave brought a wife if they could 

 get one. The building department was 



