REPORT OF BOARD OF CONSULTING ENGINEERS, PANAMA CANAL. Mr. MALTBY. The rehandling would cost considerably less than the original handling, the material being already loose. We would handle a larger percentage of solid material with the same discharge, requiring no agitating machinery. There would be the cost of a long pipe line and the levees, the cost to be absorbed in a large yardage, and it would not add materially to the unit cost. I should say that it would be safe to say that it would cost us 10 cents to dredge it; it certainly would not cost any more to rehandle it. In other words, to put it into a dam, say 40 or 50 feet high, would cost not to exceed 20 cents per yard. The CHAIRMAN. Including the wear and tear of the machinery? Mr. MALTBY. I was going on the assumption that the rehandling machinery would be additional machinery. The CHAIRMAN. Did you make any silt observations of the Chagres at Bohio? Mr. MALTBY. No, sir. Mr. STEARNS. There was one other question: What percentage is sand and what percentage is clay at Gatun? The sample you gave seemed to indicate a large percentage of sand, I think. Mr. MALTBY. As far as I know, Mr. Stearns, that is a fair average sample we showed you. It was intended to show what we consider a fair average sample of the material. Mr. STEARNS. Would not a material of that kind settle quite quickly in a scow if it were pumped into it? Mr. MALTBY. A large proportion of it would. Some might go overboard. I do not think I would recommend the use of a suction dredge to load into scows. If you are going to take it up in scows I would load it with a dipper dredge, because you do not want to mix it up so much. My idea of a hydraulic dredge was to pump it over the bank and let it go. If we were going to put it into scows, the first handling would better be with a dipper dredge. Mr. STEARNS. What would that cost? Mr. MALTBY. It would not cost much more. The plant would not have quite as much capacity. Mr. RIPLEY. For the same amount of money you could get the same capacity with dipper dredges? Mr. MALTBY. Yes, sir. Mr. RIPLEY. You put in two dipper dredges where you put in one hydraulic dredge? Mr. MALTBY. Yes. At 12.45 recess was taken. ISTHMIAN CANAL COMMISSION, DEPARTMENT OF ENGINEERING AND CONSTRUCTION, OFFICE OF DIVISION ENGINEER, Cristobal, October 14, 1905. SIR: Referring to certain questions asked me by the Board of Consulting Engineers recently, I have the honor to inclose herewith a table showing the range between high and low tide at the Panama Railroad pier in La Boca, between September 22 and October 10, 1905. You will note that the extreme range between high and low tide is given as 19.9 feet on October 1. Also that a note states that this tide was abnormal on account of a strong southeast wind. The wind evidently did not affect it to any great extent, as the range on the day before approached very closely to it. I find I was mistaken in making the statement regarding the tide record at Naos Island. I find this record has not been maintained continuously. I have no record of it at all. In fact, my records of tidal observations are not very complete at La Boca pier prior to August 1. Since that date we have gotten records at the Panama Railroad pier and at kilometer 65. The information given will, however, answer the question of the Board as to whether there was an abnormal tide during September. Evidently there was not. The previous spring tide, which occurred about September 1, had a range of 19.1 feet. Referring to Mr. Parsons's question as to the difference in the time of the tide at La Boca and Cristobal, I find,. on comparing the records for a week, that high tide at Cristobal averages eight hours and fifty-four minutes later than at La Boca; or, in other words, with high tide at noon at La Boca, high tide at Cristobal would occur at 8.54 p. m. I hope this will give you the desired information on this subject. Very respectfully, F. B. MALTBY, Division Engineer. Gen. GEORGE W. DAvs, Chairman Board of Consulting Engineers, Washington, D. C. 465A-06-23 305