has ended, the slides will, I think, undoubtedly cease also. Whether they will stop immediately or whether gradually, I do not pretend to say; but there will be a time when they will stop, probably within a year or two.

Mr. SIMS. Is there likely to be more sliding during the wet season than during the dry season?

Col. GAILLARD. The slipping of overlying clay on a rock surface is more likely to occur in the wet season. The breaks in the banks have occurred to as great an extent during the dry as during the wet season. This breaking is caused by the crushing of a softer layer near the bottom by the superimposed weight of the bank, the pressure from which in many cases forces up the crushed material, causing the bottom to rise up.

Mr. SIMS. Was the cut by the French deep enough down to give an idea of the effect of the slopes on the matter of sliding?

Col. GAILLARD. The French had a good deal of trouble with slides. The Cucaracha slide gave them a good deal of trouble, and the slide just north of Gold Hill gave them trouble also. Both of them have given us trouble. The Cucaracha slide has been dormant for several months and the slide on the east bank north of Gold Hill is almost dormant now. We are working that off and have almost overcome it.

Mr. SIMS. So the French did have trouble with slides?

Col. GAILLARD. Yes.

Mr. SIMS. Then, your conclusion is that when the work is finished the slides will be less?

Col. GAILLARD. Yes; they will ultimately cease to all intents and. purposes, and will probably greatly decrease at the end of a year or

two.

Mr. COVINGTON. How serious in its effect upon navigation in the canal would the greatest slide have been?

Col. GAILLARD. The greatest slide, so far as interference with navigation is concerned, was the Cucaracha slide in the fall of 1907. That was a true slide of clay sliding on an inclined surface of rock, and went completely across the canal. That would have absolutely blocked navigation if it had happened on the bottom then, but we were not then at the bottom. Since 1907 there has never been a slide that would have prevented a vessel from going around it in a 300-foot channel. In other words, we have always had width on the bottom sufficient for vessels to pass around since that slide of 1907, and navigation would not have been interrupted at any time since by a slide. Mr. HAMLIN. You are now taking off portions of the bank of the

canal?

Col. GAILLARD. Yes; that is done to lessen the weight. That was done with the chairman's approval.

Mr. HAMLIN. Do you expect to continue that work?

Col. GAILLARD. Yes; we expect to do a great deal of that during the dry season, when conditions are most favorable.

Mr. HAMLIN. That will have the effect of largely decreasing the probability of future slides?

Col. GAILLARD. Yes; undoubtedly.

H. Doc. 680, 62-2-13

Mr. SIMS. Was there any considerable time elapsed between the time the French ceased their work and you commenced your work where these slides occurred?

Col. GAILLARD. The French worked continuously in order to hold their charter. They had a force of seven or eight hundred people working when the United States took control.

Mr. SIMS. Was there a period of time when there was a cessation of work?

Col. GAILLARD. No, sir; there was some work in progress all the time.

Mr. SABATH. Then, it would be advisable to keep the shovels, so that in case you should have these slides again you could remove the material in short order.

Col. GAILLARD. Well, for a year or so I think it will be advisable to keep a few shovels ready for work. They could work on the 95foot berms or benches, and the dredges could work in the canal, and we would thus have facilities for removing a slide then that we have not now, because we could work it both with shovels and dredges, which would be a great advantage. I do not think any large number of shovels would be necessary.

Mr. SABATH. What material would be used for that concrete work that you have started?

Col. GAILLARD. On the revetment wall?

Mr. SABATH. Yes, sir.

Col. GAILLARD. We are using cement and Chagres River gravel. Mr. SABATH. Are pebbles better than crushed stone?

Col. GAILLARD. Not better, but much cheaper. We get gravel for 29 cents, and crushed stone would cost 80 cents or $1. It is amply good for the purpose. It is simply a question of economy. If crushed stone were cheaper I would use that.

Col. GOETHALS. Strength is not an important consideration in that work. If strength were required stone would be better.

Mr. SIMS. It would be much cheaper to remove this material by barges than to remove it, as now, by steam shovels?

Col. GAILLARD. It would not be cheaper to remove large rock in that way. To remove large rock under water would be very expensive, but for ordinary crushed material from slides, the dredges would remove it much more economically than the shovels.

The CHAIRMAN. If the slides were to fall in after the canal is filled with water, would not the water aid you materially in removing it? Col. GAILLARD. I do not know whether it would to any great extent or not; it might do so.

Mr. SIMS. There would be no current, of course.

Col. GAILLARD. No; practically none.

The CHAIRMAN. But water is a universal solvent, and would dissolve it?

Col. GAILLARD. Yes; it would soften clay and earth. I would not, however, feel apprehensive of a slide blocking the entire canal at places where the slides are likely to occur.

Mr. STEVENS. In your annual report you give a statement of the amount of increase of cubic yards on June 30, 1911, over the estimate made July 1, 1910, of 4,600,000, stating that the increase was due to slides. Now, what change of plans in that time required an increase of excavation?

Col. GAILLARD. There was no change of plans that required any increase of excavation. We simply, with the funds available and the equipment available, were able to take out more material than we estimated that we could take out.

Mr. SIMS. Under the plan that had been adopted?

Col. GAILLARD. Yes, sir; we were working practically under the same plans.

Mr. SIMS. I notice in your report that you state that several contracts that is, small contracts-had been let. To what class of contractors were they let, and what was the class of work?

Col. GAILLARD. The contracts let were for excavation by handwork, in rock and earth, and for clearing the canal prism. Three of the contracts were let to American citizens. The list is as follows: Statement showing work done by contractors for the central division.

NOTE.-On Mar. 31, 1911, on account of it being found that the classification of earth, soft rock, and hard rock given the contractor in the "Bids for excavation" was not correct, a new contract was entered into with Mr. McFarland, by which all remaining excavation was to be done at the flat rate of 34 cents per cubic yard, regardless of class of material.

Mr. STEVENS. The point I wanted to know was whether it would be probable that a similar condition would exist after the permanent use of the canal, so that such contracts might be had, if necessary, for any slides or work needed subsequently to be done.

Col. GAILLARD. I would think that the removal of slides, and work of that character, could best be done by the person in charge of the operation and maintenance of the canal with the forces employed by him.

Mr. STEVENS. And not depend on contractors?

Col. GAILLARD. I would not depend on them.

Col. GOETHALS. The conditions surrounding the small contracts were that the localities were inaccessible to our steam shovels, and it was more economical to have these small amounts removed by handwork than to build and maintain trestles across the river for the transfer of our plant to these localities.

Mr. STEVENS. So no increase in the cost of completion will be expected because some contracts may be let if necessary?

Col. GAILLARD. I think not.

Mr. STEVENS. Do you anticipate that the cost of maintenance will be decreased by reason of the work you are doing under the orders of the chief engineer upon the upper levels?

Col. GAILLARD. I should think that cost would be materially decreased both during construction and afterwards, during the maintenance of the canal.

The CHAIRMAN. Instead of relying upon outside work after the canal is finishd to keep it in the proper state, it would be better to keep the equipment in repair, and, I think, for a year or two at least it would be the part of wisdom to keep the shovel equipment up for maintenance work on the canal.

Mr. HAMILTON. The idea I had in mind was this, that in the maintenance and care of the canal you would take into consideration that it would be necessary to have certain machinery to do certain work, and that you would have a complete outfit for that purpose, not only to meet emergencies, but to meet the ordinary routine work necessary in connection with the maintenance of the canal.

Col. GAILLARD. I would hold some of the equipment, and I would reserve whatever disposition is made of the rest of it, the proper amount for the maintenance of the canal during the first year or two. I do not think there would be any great amount of work in the way of the removal of slides after a couple of years; probably not after a year, but that, of course, I do not know.

Mr. STEVENS. But you do suspect that for some time there will be some cost of maintenance in the way of these things you have indicated?

Col. GAILLARD. It might be considerable the first year, but I think it will largely disappear after a year, or after a couple of years or so. Mr. STEVENS. But there would always be some considerable expense of maintenance along your division?

Col. GAILLARD. There would always be some expense of maintenance along that division. The only point where I would anticipate any considerable amount of expense for maintenance is where the Chagres River and the canal meet at Gamboa, where we got out this morning. That locality has 5 or 6 miles of lake above it to catch and hold the silt and sediment before it reaches the canal; but in time a considerable quantity might find its way down. If much silting should occur at any place, that is where I would look for it.

Mr. STEVENS. That brings me to the statement in your report, on page 144, in which you state that you are saturating certain material and sluicing it into the bed of the Chagres. Is that what you allude to as silt that may come down into the bed of the canal?

Col. GAILLARD. No; we have sluiced no material above the Gamboa bridge. That material that we sluiced into the Chagres River settled in the old bed of the river at a level below the bed of the canal, as the bed of the channel is lower than the bottom of the canal.

The CHAIRMAN. Is it not the property of flood water, when its progress is arrested, to immediately deposit whatever sediment it carries?

Col. GAILLARD. It immediately deposits the heavy material, but not the fine silt. If the heavy material is deposited when it strikes the slack water it would be deposited above the Gamboa bridge, but the lighter material might cause some amount of dredging, but no unreasonable amount, I should say, within the canal prism.

Mr. STEVENS. I would like to call your attention to the plant in your division that would remain after the canal is finished. In what condition would the plant be, that is, the cars, the trains, locomotives, the plows, steam shovels, etc.? Would they be available for all sorts of construction work?

Col. GAILLARD. They could be kept in such condition as they are now being kept so that they would be available for any class of construction, or we could, as we dispense with the need of certain machines, work them until they broke down and put them in the yard without repairs and leave them in that condition and still have enough left to continue the work. Whichever course is the most economical will be adopted. The work can be finished satisfactorily, and there can be left on hand an ample supply for the maintenance of the canal, because we will probably work up to the very last month not less than six or eight shovels.

Mr. STEVENS. The policy then will be, as adopted by the commission, that the most economical plan of using the equipment will be the one that will be in effect?

Col. GAILLARD. Yes; undoubtedly.

Mr. STEVENS. So that, so far as you are now advised, you would not seek to keep the plant in shape for use elsewhere?

Col. GAILLARD. No; I would not.

Col. GOETHALS. Under our system of cost keeping we will absorb the total cost of the plant by the time the canal is completed. Whatever we can get for that plant after we finish with it is so much salvage, but the present indications are that the plant will amount to nothing but junk, so the necessity of keeping it up in first-class shape is not apparent.

Mr. STEVENS. Do you think it would be in the interest of economy, in the final result, to keep the plant up in better shape in order that it could be sold at a higher price than as junk?

Col. GOETHALS. Yes.

Mr. STEVENS. Would you take that into consideration?

Col. GOETHALS. Yes, sir.

Mr. STEVENS. Would you take into consideration the fact that the United States might use some of that plant in its public work? Col. GOETHALS. I have thought of that, and have reported on a bill introduced in Congress seeking to transfer the plant to the United States, but I can not see any public work on which the United States is engaged that would require such equipment.

The CHAIRMAN. The gentleman from Louisiana introduced a bill which was referred to Col. Goethals.

Mr. STEVENS. Then, your report is that there is no public work of such consequence, of which you are aware, in the country, and of such character, on which this plant could be used to advantage? Col. GOETHALS. Yes, sir; that is the substance of the report. Mr. Escн. I understand that Secretary of the Interior Fisher, who recently returned from Alaska, intimated that he might favor the construction of a railroad from the coast into the coal-bearing