196 
REPORT ON THE PANAMA CANAL 
breaks, will move into the cut, 7,000,000 cubic yards will have to be removed 
before the slides are entirely stopped. Mr. Comber, Resident Engineer of the 
Dredging Division, assumed a surface parallel to the surface existing on Octo- 
ber 14, the date of the last complete survey, and 45 feet below it, on which 
basis 13,000,000 cubic yards would be the quantity to be handled. He 
thinks, however, that a mean between the two amounts may be more nearly 
correct, which was the method of arriving at the 10,000,000 cubic yard 
figure which has appeared in the press. It is at best only a guess. It must 
not be inferred from this that the Canal will be closed until this amount is 
dredged, for such is not the case; on the contrary it is the intention to pass 
ships as soon as the channel is secured through the remaining 600 feet, and 
there are reasonable grounds for assuming that a channel through the ob- 
structed area can be maintained. 
The active West Culebra Slide extends 2900 feet along the Canal, and 
1350 feet at right angles to it measured from the axis of the Canal to the 
furthest point of the slide. 
Of the slides now quiescent, the most important is the Cucaracha. 
General Goethals writes of it, in the article already mentioned: 
On January 20, 1913, a break occurred at Cucaracha by which the rock 
bluff which was holding back the upper mass of clay broke at or below the 
bottom level of the Canal, completely filling the prism with clay and rock, 
reaching to 69 feet above sea level on the opposite or west side of the cut. The 
length of the prism so filled was 1600 feet. Steam shovels were scarcely able 
to keep pace with the movement, tracks were covered and disarranged, shovels 
overturned, and the difiiculties of transportation increased, since only tail 
tracks sufficient for two or three cars could be maintained. Furthermore, the 
soft material increased the difficulties of the dumps. As the movement con- 
tinued the clay broke farther and farther up the hillside. 
The Cucaracha Slide, as stated, extended 1600 feet along the Canal, 
and 1880 feet at right angles to it. 
Dominant Importance of the Three Great Slides. — ^According to Mr. W. 
G. Comber, Resident Engineer in charge of Dredging, the acreage of the 
three great slides is as follows : 
In contrast with this, the total area of all other slides is 112 acres. 
The dominance of the three great slides appears even more marked 
when the amounts of excavated and moving material are considered. 
West Culebra Slide 
East Culebra Slide. 
Cucaracha Slide 
60.8 
70.5 
60.4 
Total 
201.7 
