REPORT ON THE PANAMA CANAL 
195 
THE THREE GREAT SLIDES 
The slides which led to the closing of the Canal on September 18, 
1915, were the great East Culebra and West Culebra Slides. General 
Goethals has described these slides in an article prepared for the press, 
iinder date November 15, 1915, and from this article the following 
statements are taken: 
The East Culebra SUde began on October 14, 1914, without any warning 
and a section of the east bank north of Gold Hill settled vertically 20 feet. 
This section measured 2,000 feet (now extended to 2,700 feet) along the prism 
face and extended back 1,000 feet from the axis of the Canal, generally along 
an irregular curved line. The top of the bank was from 300 to 350 feet above 
sea level, and the extension of the groimd eastward was relatively flat country. 
In the settlement, the upper portion which broke away remained practically 
parallel to its original position, and the benches which formed the upper part 
of the shde had not changed their relative positions, though they were badly 
broken up, while the lower strata were squeezed out across the Canal. Subse- 
quently the broken mass moved into the cut, reducing the depth of the water 
from 45 feet to 9 inches at one point. Until August, 1915, the dredges were 
able for the most part to keep up with the movement as it came down, and 
probably would have been able to maintain this condition had not a movement 
occurred on the west bank, necessitating work on this side to the detriment 
of the east side. 
A crack was found on the slope of Zion Hill in June, 1914, but observa- 
tions made upon it showed no movement and the soHdity of the hill was never 
doubted. Subsequent to the break on the east side, a gradual but general 
breaking up of the west bank followed, and the crack on the slope increased in 
size and new ones developed farther up the hill, until finally one extended to 
the elevation of 480, the limit of the present break. The movement into the 
cut from the west bank occurred early in August, 1915, when a section of Zion 
Hill broke away and settled down. The edge of the break on this side is also 
a curve. 
The movements from the two sides are towards the central portion of the 
enclosed area, and at this central portion is the obstruction to the channel. 
It first appeared as an island forced up from the bottom, then as a peninsula 
projecting from the east bank, and finally was pushed entirely across the 
channel completely closing it 
The length of the slides, which are directly opposite each other, is approxi- 
mately 2,200 feet (the channel through which is navigable with the exception 
of 600 feet) ; the banks are 300 to 350 feet above sea level on the east and 
extend up to 480 feet above sea level on the west. The area of the territory 
affected on the east side covers 81 acres and on the west 78.5 acres. 
Assuming that all material lying above planes extending from the out- 
side limits of the bottom of the prism, reference 40, up to the limits of the 
