The following text may have been generated by Optical Character Recognition, with varying degrees of accuracy. Reader beware!

VITH THE TOWN OF BALB OA ON THE RIGH bE ed a half-mile back from the canal and 3 pushed its way resistlessly across the basin, a tropical glacier, in fact, ad- vancing at a uniform rate of about 14 ft. in 24 hours, destroying tracks and actually rising on the west bank until the only track left upon which the dirt trains could get through was 'the 95-ft. level. Gangs of workmen are constantly kept busy laying new tracks and trains rush im and" out like shuttlecocks--and yet, after two weeks of effort, the impression upon the slide was scarcely perceptible. Cucaracha is the true form of slide. Ee ees Lack of Lateral Support There is another kind of slide con- tinually occurring. It is no uncommon thing to walk along a track and then returning an hour later to find the track 'lifted at least: 1 it. One notes aE ge Re ee THE it by the fact that he has to step down from which was formerly the bottom level. Lieut. Col. Gaillard reports that he was once lifted 6 ft. in five minutes from the bottom of the cut, but so imperceptible was the move- ment that he thought the steam shovels were sinking and not he rising. This kind of slide, the most notable of which is on the west bank at Culebra, is caused by the absence of the lat- eral support to the banks which was afforded before the excavated . ma- terial was removed from the canal basin. The great pressure evercised by the banks, estimated at 400 lb. per sq. in. enough to burst any boilerg crushes the underlying layers of soft materials, causing. a settling of the banks and a consequent bulging up at the point of least resistance, which is obviously the bottom of the canal, re- HARBOR WITH ROCK QUARRY ON THE EXTREME RIGHT sulting in its elevation, including tracks, locomotives, steam shovels, drills and other equipment, to a dis- tance -of 30 t, or more, Then (the . banks themselves begin to move resist- lessly into the cut, filling the basin, and the work of excavation begins all over again. The Culebra slide, being in fact a combination of many slides of this character, exceeds now in actual area the great slide at Cucaracha--about 7,900,000 cu. yds. having been taken out of it and probably 3,000,000 cu. yds. remaining. But the estimates must undergo constant revision as the slides are constantly recurring. The great Culebra cut is nearly 9 miles long and there are over 20 slides along its, length. It no longer sur- prises the workmen to see a hump in the. canal bed, involving, say, 50,000