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A VIEW ALONG THE BOTTOM IN TIIT CULEPRA CUT Where the cut was not impeded by the slides it looked just like this picture. When the water was let in about nine-tents of the cut was in

this condition

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TIIT CUT AT BAS OBISPO, SITOWING DEELEST PART OF TIME EXCITATION The intention of the canal engineers is to cover the banks of the canal through Culebra Cut with vegetation, in order to prevent those small slides

that come down through crosion. When the ships of the future use the canal they will sail between banks of tropic green

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X

SLIDES FROM BOTII BINKS BLOCK TITI, CINIL: SEPTEMBER 20, 1913 "The slides seem to be maneuvered by the hand of some great marshal and sent forth to prej in every way calculated to put the canal engineers to discomfiture; now they are quesceni, attempting to lull the engineers into it false security; now they come in the dead of night, spreading chaos and disrupting everything in whatever direction they move" (sce text, page 133).

BATTLING WITH THE PANAMA SLIDES

115

ness.

of the canal. At one time Cucaracha any fossil remains, and so their age canipicked up a steam shovel, track and all, not be fixed with any degree of definiteand moved it 50 feet away, but still The Bas Obispo formation is of standing ready for operation as though volcanic origin and crops out at Bas nothing had happened, except that it was Obispo, Miraflores, and Old Panama. cut off from the dirt-train tracks.

At

The Las Cascadas agglomerate is made another place and time Mohammed did up of basalt breccia, cemented together not have to go to the mountain, for it with volcanic clay and tufa and other came to him; so at Panama a shovel was lava flows. able to make a hundred trips or more Culebra Cut contains fossils of seaback and forth along the base of a slide living animals, thus proving, along with without moving a step closer to the dirt, other evidence, that this great barrier for the slide came down just as fast as

which has stood between man and his the shovel worked.

dream for more than four centuries was · During their history the Culebra Cut once at the bottom of the sea. slides destroyed over 200 miles of rail It is stated that Gold and Contractor's road track. Sometimes a slide would hills, which now stand as the huge posts come down, forcing one track out of po

of the Panama Gateway, are composed sition, passing under the next one with of comparatively young volcanic rock out disturbing it at all, and then upheav- blown up to a heighit some 300 feet or ing the material under the third track more above their present summits, and mayhap as much as 10 or 20 feet. that they settled down to their existing

All manner of efforts were put forth level soon thereafter. The evidence of to prevent slides. It was once proposed the rocks of the Isthmus is that there that cutting off the top of the bank above were two eras of volcanic activity, the the cut would prevent those that devel one of terrific force and the other much oped through structural breaks. But this more gentle, with a long quiescent period work was vigorously prosecuted for between them, awhile with no important bearing on the During the first volcanic era islands ultimate result. At another time it was arose in the shallow ocean that linked the suggested that a revetment of concrete Atlantic and the Pacific. During the along the banks of the cut would protect second period the whole land arose and it, but this was a failure also. The water the rivers became active, assorting the that seeped down from the surface got rocks as they hurried to the sea. The in behind the concrete and caused it to original bed of the Chagres at Gatun, as loosen its hold and scale off.

it existed then, is now 375 feet below seaAt another time it was suggested that level. After this the ground sank to 8 letting water into the cut would tend to feet below its present level on the Atlandevelop an equilibrium and thus prevent tic side and to 25 feet below its present additional slides. But this method of level on the Pacific side. This level seems treatment succeeded no better than those to have been maintained until a time apmethods which were tried out before; proximating the dawn of the Christian and so the settled policy became one of era, when it rose to the present level. inviting all slides that intended to come Interesting proof of this is afforded down to do so quickly, so as to have it all some So miles from Ancon. The Indians over with.

there have been using the contents of a

shell mound, found at the base of a 75WHAT CAUSES THE SLIDES

foot hill, for burning lime. The plain The causes of the slides at Panama here is about 25 feet above sea level. must be traced to the geologic history of The mound contains many varieties of the Isthmus. There are ii groups of shells and much broken crockery, indibedded rock and six of igneous rock on cating that it was once used as a kitchen the canal line. The two oldest rocks are midden. \bout 2 inches of soil cover the Bas Obispo formation and the Las these deposits, and near-by is a place Cascadas agglomerate. Neither contains which shows that it was used as a canoe

CUCARACHA SLIDE BEFORE THE CUT WAS FLOODED

This slide “so prevented the work from going forward that Colonel Goethals finally determined to let the water in and to dredge her out” (see text,

page 141). This is the last photograph taken before the cut was nooded

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