Senator MORGAN. So that there could be no want of water in conducting the dredging process right against the front of the opposing wall, whatever it might be, with the water following behind?

Colonel ERNST. Yes; but you could only use 2 or 3 machines, for instance, instead of 100, as they talk about using.

Senator MORGAN. But if the two or three machines could do the work of a hundred, it would make no difference, would it?

Colonel ERNST. No, sir.

Senator MORGAN. I think it is probably confessed that a dredge can do more work than a steam shovel, no matter how big it is, if the dredge is big enough.

Colonel ERNST. I suppose that is so.

Senator MORGAN. So that as an implement of work, in dredging or opening up a channel, the dredge is the preferable instrument, other things being equal, size and strength, etc.?

Colonel ERNST. Yes.

Senator MORGAN. If you were dredging a sea-level canal from the 40-foot contour to Gamboa, have you a sufficient knowledge of the topography at Gamboa and in that vicinity, between that and Bobio, to say whether you would follow the line of the River Chagres, or whether you would cut upon the right bank of the Chagres?

Colonel ERNST. Oh, yes; you could not follow the line of the Chagres River.

Senator MORGAN. You could not?

Colonel ERNST. No, sir; it is too tortuous. it a great many times.

You would have to cross

Senator MORGAN. I mean, of course, the general line of the Chagres Valley.

Colonel ERNST. You would keep in the bottom of that valley, certainly.

Senator MORGAN. You would prefer to take your canal as straight as you could make it right across the river wherever you encountered it, but along the valley, rather than to encroach upon the hills on the right bank?

Colonel ERNST. Yes, sir.

Senator MORGAN. Is there any difficulty, in your estimation, in dredging a sea-level canal from this 40-foot contour up to Gamboa or the vicinity of it? Is there any physical obstacle there?

Colonel ERNST. Only the difficulty of getting it done in any reasonable length of time. You would have a very narrow point of attack. You could not, as you would if you were using land transportation, attack it at a great many different points-along, we will say, the whole length of the canal. By the method you describe you could only be attacking it at one point-the width of the canal in front.

Senator MORGAN. You would have two points: one from each side of the Isthmus?

Colonel ERNST. Certainly.

Senator MORGAN. And you could attack it with as many dredges as was necessary to cover the whole front of your operations? Colonel ERNST. Yes, sir.

Senator MORGAN. Is there any physical obstruction or difficulty in the way of that?

Colonel ERNST. I do not know of any at all.

Senator MORGAN. At Gamboa you encounter the rock at the level of the sea?

Colonel ERNST. Yes, sir.

Senator MORGAN. How far is that rock beneath the topographic surface there?

Colonel ERNST. About 50 feet. The ground is about 50 feet above the level of the sea, I think.

Senator MORGAN. So that, after digging down for 50 feet, you would strike rock that was at the level of the sea, and you would have to go through that 40 feet below the level of the sea?

Colonel ERNST. Yes, sir.

Senator MORGAN. That would be 90 feet. Do you know of any physical or engineering difficulty that would be an obstruction-what we would call an obstruction-to the cutting of a sea-level canal along the line I have mentioned to Gamboa or in that vicinity? Would you find any impediment there that an engineer would shrink from and say "I can not accomplish it?"

Colonel ERNST. No, sir; there is nothing that is impracticable there. Senator MORGAN. Between Gamboa and Obispo is about 3 miles, is it not?

Colonel ERNST. Yes, sir.

Senator MORGAN. We speak of the little village of Obispo

Colonel ERNST. I think it is a little more than that. I can tell you in a moment. [After inspecting map.] It is 14 miles.

Senator KITTREDGE. You misunderstood the question. You are referring to Bohio there.

Senator MORGAN. You are referring to Bohio, are you not?
Colonel ERNST. Yes, sir.

Senator MORGAN. From Gamboa to Obispo, I mean.

Colonel ERNST. It is half a mile there-a very short distance. I do not believe it is more than half a mile.

Senator MORGAN. So that they are practically one location, speaking in the general sense. There is no special elevation or abrupt elevation of land between Gamboa and Obispo, is there?

Colonel ERNST. No, sir; there is not. The river comes in there. The rivers unite. The point between the rivers is very high ground. The Obispo River comes down and joins the Chagres River very near

there.

Senator MORGAN. Yes.

Colonel ERNST. And of course they are at the same level where they join.

Senator MORGAN. Yes. And then there is a little valley through which the Obispo runs to join the Chagres?

Colonel ERNST. Yes, sir.

Senator MORGAN. And the canal would go right up that little valley? Colonel ERNST. Yes, sir.

Senator MORGAN. Is the ground abrupt and high on either side of it? Colonel ERNST. Yes, sir.

Senator MORGAN. Particularly so?

Colonel ERNST. Yes, sir; there is where you approach the Culebra Cut. That is the beginning of it.

Senator MORGAN. That is the first approach you make toward the Culebra Cut?

Colonel ERNST. Yes, sir; that is what you may call the beginning of the Culebra Cut.

Senator MORGAN. You go up the Obispo River from Gamboa, and then you go into the hill at the proper angle, called the first Emperador, and then Culeba?

Colonel ERNST. Yes, sir.

Senator MORGAN. Then your work is through that ridge, and from that over to Miraflores?

Colonel ERNST. Yes, sir.

Senator MORGAN. Have you ever examined the plan of the dam that the majority of the consulting engineers propose to put in at Gamboa? Colonel ERNST. They did not prepare any plan, Senator; they submitted no design for that dam.

Senator MORGAN. They submitted no design?

Colonel ERNST. No design at all. They described it as an all-masonry dam or an earth dam with a masonry core; but there is no design for it. Senator MORGAN. They give the height of it?

Colonel ERNST. Yes, sir; but no design.

Senator MORGAN. And an indefinite length upstream?
Colonel ERNST. That is all they say. They give the height.

Senator MORGAN. They do not give a cross section of it, do they?
Colonel ERNST. No, sir; they give no design at all.

Senator MORGAN. In your studies of this country, which I have no doubt have been entirely profound and very careful, what is your view or your opinion as to the practicability of putting a dam at Gamboa of the height that the majority of the committee propose? Colonel ERNST. I believe it is practicable to build it.

Senator MORGAN. About how high is that?

Colonel ERNST. One hundred and eighty feet.

Senator MORGAN. That would throw the water back beyond Alhajuela probably?

Colonel ERNST. Yes, sir.

Senator MORGAN. I believe they give measurements for that as to the size of the lake it would form?

Colonel ERNST. Yes, sir.

Senator MORGAN. As to the cubic contents of the lake?

Colonel ERNST. Yes; they do give that, too.

Senator MORGAN. Would the water impounded by such a dam as that be sufficient to fill the prism of a canal between, say, Obispo and Miraflores?

Colonel ERNST. I have not in mind what that volume is, Senator, but I should think it would.

Senator MORGAN. On the other side, if a sea-level canal is dredged in from the 40-foot contour, near these islands, I suppose that would be through the level country, the low country, to Miraflores, and if that canal should be 40 feet deep below the level of the sea, and, say, 300 feet wide, would a canal with a prism of those dimensions dispense with the necessity of putting in a sea-gate?

Colonel ERNST. I do not think it would.

Senator MORGAN. Why?

Colonel ERNST. I think the volume of water that is to go in there has got to get through somehow-you mean for a sea-level canal? Senator MORGAN. I mean a sea-level canal, yes, with a rise of water 10 feet or 10 feet above ordinary sea level at high tide.

Colonel ERNST. That is one of those problems that is not capable of definite solution; but I made some such study as this, if it interests you at all [illustrating by pencil sketch]. We will suppose that this represents the Panama end of the canal, and this the Colon end. This distance is 47 miles, that height is 10 feet, and that height 10 feet [indicating]. Supposing the slope to be uniform all the way from Panama to Colon, which is the most favorable condition that you can have for velocities-that involves filling into that canal a prism of water which is shown there [indicating]. That can be computed. I have computed it.

The velocity required to get that volume of water in there is greater than you can possibly get up on that slope, which shows to me that that tidal influence will not extend clear over to Colon. It will only extend a little less than halfway. That gives you a slope which can be computed, and from that I get a velocity of 5 or 6 feet a second for an average. It is not going to be the same at all times. There can not be any average velocity there. It will be much greater at one time than it will be at another time; but I should expect a velocity of 6 or 7 feet a second there at least.

Senator MORGAN. At high tide?

Colonel ERNST. Yes, sir; at high tide and at low tide. It would flow in at one time and flow out at the other time.

Senator MORGAN. So that you think that that would not dispense with the necessity for the sea gates, even if that canal is 300 feet wide? Colonel ERNST. No, sir; I think we will have to have sca gates there still.

I sup

I think

Senator MORGAN. Suppose you make it 400 feet wide? Colonel ERNST. I do not know where the limit will come. pose it would come in time, but not with a width of 400 feet. you would still have to have the sea gates with a width of 400 feet. Senator MORGAN. I called your attention to it because some of the engineers who have appeared before the committee have said that a canal with a prism of 300 feet extending from Miraflores out to the sea would dispense with the necessity for the sea gates.

Colonel ERNST. That is a surmise, for which they can not give any convincing proof.

Senator MORGAN. A sea-level canal there would be 40 feet below sea-level according to the project, would be 200 feet wide, I believe it is, and the rock as developed by the borings through the Culebra Heights would average, according to some estimates that have been made here, 25 feet above sea-level; and that rock is all described, after you have reached it and until you get through it, as a solid cube of rock, of course with dikes in it and fissures and one thing and another; but, practically, in operations and in work it would be estimated as a solid cube. It would be, then, 65 feet in depth, 200 feet wide, and 8 miles long. That would be about the size of it, would it not? Colonel ERNST. Yes, sir.

Senator MORGAN. It would take a long time and a great deal of hard work to get that cube of rock out of there, would it not? Colonel ERNST. Yes, sir; a great deal.

Senator MORGAN. Was that one of the deterrents against the construction of the sea-level canal?

Colonel ERNST. Yes, sir.

Senator MORGAN. On account of the time it would take and the money it would cost?

Colonel ERNST. Yes, sir.

Senator MORGAN. Did any of the engineers suppose it would be

otherwise impracticable?

Colonel ERNST. No, sir.

Senator MORGAN. In an engineering sense?

Colonel ERNST. No, sir; none at all.

Senator MORGAN. They thought that rock could be taken out?
Colonel ERNST. Oh, yes.

Senator MORGAN. The two plans that were submitted were a lock canal and a sea-level canal; that is to say, a lock canal over the whole width of the Isthmus, in some form, and a sea-level canal through the whole width, in some form, with practically the same line, the same curvatures, and all that. Was any intermediate plan ever suggested or acted upon by the Commission?

Colonel ERNST. You mean our commission of 1901?

Senator MORGAN. I mean the board of consulting engineers.

Colonel ERNST. They studied three or four different projects, different arrangements of dams.

Senator MORGAN. But they were all either lock canals through and through, or else they were sea-level canals through and through? Colonel ERNST. Yes, sir.

Senator MORGAN. And an intermediate plan of a canal partly sealevel and partly a lock canal across the Culebra Heights was not passed upon by them?

Colonel ERNST. No, sir; unless you call that part leading up to Gatun, between Colon and Gatun, a sea-level canal. It is at the level of the sea.

Senator MORGAN. Yes; from Gatun up to Colon, or out to sea?
Colonel ERNST. Yes.

Senator MORGAN. That would be a sea-level canal.

Colonel ERNST. There is about 7 miles of it there.

Senator MORGAN. That would be, necessarily, a sea-level canal-that much of it?

Colonel ERNST. Yes.

Senator MORGAN. The two propositions that were submitted to the consulting board, as I understand, upon which they passed, were the lock canal, practically covering the whole width of the Isthmus, or a sea-level canal covering the same width.

Colonel ERNST. Yes, sir.

Senator MORGAN. But the question of the possibility of an intermediate plan of which, say, two-thirds would be sea-level and onethird lock canal was not considered?

Colonel ERNST. They considered a number of things, but I am not quite familiar with what they were. They made a number of studies besides. I think they discussed that.

Senator MORGAN. But they did not pass upon any such proposition as I suggest, because it was not submitted to them?

Colonel ERNST. No, sir; it never was worked up in detail.

Senator MORGAN. That was their duty, or what they were invited to do-to pass upon the simple question of a lock canal over all or a sea-level canal over all, across the Isthmus? The other projects, or