No. 3.-Blueprint showing profiles of borings on or near the axis of the Gatun dam. No. 4.-Blueprint showing location of borings for the Gatun lock site, and the axis of the location adopted for the lock. No. 5. Series of six blueprints showing profiles on boring lines to develop the lock site at Gatun.. Nos. 6 and 7.-Blueprints showing borings on cross sectional lines through the lock site and the relative position of the lock walls. No. 8.-Blueprint showing the stratification of material and the top of lock wall and level of lock floor on a profile along the axis of the locks, and also profiles on parallel lines 170 feet east and west of the axis of the locks. The Commission at its meeting on November 20, 1906, directed the continuance of examinations to furnish information for the designing of locks, by sinking test pits under the lock walls, and the testing of block samples from these pits, to determine the bearing power of the material and other physical characteristics. The materials disclosed by the observations of the strata underlying the lock site show, below the surface soil, either what is denominated by the engineers in the field as "indurated clay or chopped sand and clay." These terms may be misleading. The chopped material is different from the "indurated clay" and seems to be a sort of hardpan or conglomerate, either of which will make a good foundation. Referring to the physical, and not to the geological character of these formations, the "indurated clay" has a rock-like consistency which resists compression and erosion, and makes an entirely satisfactory foundation for the proposed lock structures. This is established by the borings and by the exposure of the material in the French work at the dry dock at Cristobal. By the term "chopped," in connection with the other material, is designated the method found most rapid and economical in penetrating it with boring tools. While a diamond drill was used in the so-called "indurated clay," a chopping bit was found most useful in the other material. It could have been taken out in cores by a diamond drill, and, in fact, this process was used at times. The terms are not intended to convey an impression of the value of their physical properties for a lock foundation. An opinion of the relative values of the two materials for foundation purposes is expressed in correspondence by Mr. Stevens, chief engineer, as follows: It will be noted that under the so-called indurated clay in cross sections 1, 2, and 3 exists what is called blue clay and sand-clay, gravel, and fine sand, etc. This material, while not so hard as the so-called indurated clay, is in every respect an equally good and sufficient foundation in my opinion for the locks or a structure of any weight or importance. In fact, if there were not a particle of indurated clay in Gatun Hill I would not have the slightest hesitancy in founding the whole structure on this material. I beg in this connection to inclose under separate cover a sample of this material, which was taken as a core from the borings as it is found in cross section 1 as the material underlying the indurated clay, and I think you will agree with me that there is no doubt whatever as to its character for foundation purposes. I believe it is as good as indurated clay and good enough in any case. We know of no foundation for the report "that the proposed lock on the Pacific side has been changed some 2 or 3 miles from the orig inal point designated." The locks, both at Pedro Miguel and Sosa, occupy substantially the sites chosen by the minority of the advisory board. These locations were necessarily general. When special examinations were made, it was found that the rock foundation for the locks at Pedro Miguel did not extend over the entire area covered by the structure, and a slight shifting of their position may be advisable, but there have been no other changes contemplated." In conclusion, we state that the investigations which the Commission has continued have thus far led to no disclosure of extraordinary difficulties requiring changes of previous plans. The continuation of surveys has for its object the complete adaptation of the design of locks and other features of the plan to the existing surface and subsurface conditions. There is nothing in the later examinations made affecting the practicability or permanence of the Gatun dam. Very respectfully, MORDECAI T. ENDICOTT, Chairman Engineering Committee. T. P. SHONTS, Chairman Isthmian Canal Commission. ISTHMIAN CANAL AFFAIRS, OFFICE OF ADMINISTRATION, PANAMA CANAL BUILDING, Washington, D. C., January 22, 1907. SIR: In further reply to your letter of January 8, 1907, requesting complete information relative to borings upon the Gatun and Pedro Miguel lock sites, I beg to forward herewith a copy of a letter fron the chief engineer, Mr. John F. Stevens, under date of January 12 1907, reporting more fully upon the subject of your inquiry than in his cable of the same date, which I laid before you in my letter of the 14th instant. It will be seen that this report confirms fully, after further study of the examinations, the data and conclusions given in his cable with respect to the Gatun and Pedro Miguel lock foundations. It further reports a series of 36 borings extending to or below sea level upon the site proposed for the Gatun dam spillway, with the most satisfactory developments. Your attention is also called to that portion of the report relating to examinations across the valley of the Chagres, upon the lines of the dam, and the satisfactory indications set forth, as bearing upon the successful founding of that structure. I shall take pleasure in forwarding to you promptly further reports and data upon these investigations as they come to hand. Very respectfully, Hon. J. H. MILLARD, T. P. SHONTS, Chairman. Chairman Senate Committee on Interoceanic Canals. ISTHMIAN CANAL COMMISSION, DEPARTMENT OF CONSTRUCTION AND ENGINEERING, Culebra, January 12, 1907. SIR: I beg to acknowledge receipt of your cable of January 9, reading as follows: Cable, for information Senate Committee on Interoceanic Canals, statement of results all borings and examinations at Gatun dam and lock site and Pedro Miguel lock site. Must have statement this week, but desire you follow cable with greater details by mail. I have cabled you to-day a long reply, and beg leave to confirm by letter as follows: We have taken time to go over again very carefully all of the borings made both at Gatun and Pedro Miguel, and the result, from my point of view and my engineers, who have carefully watched the work of exploration personally from its inception down to the present time, is as follows: One hundred and twenty-seven holes have been bored on the site of the locks at Gatun, these borings covering an area of 1,200 feet wide and 4,200 feet long, and show conclusively, in our opinion, that it is possible to build three duplicate locks, this area having usable dimen-. sions of 100 by 1,000 feet, with foundations for the lock walls at all points supported on a firm and suitable soft rock. All of these holes have been carried well below the bottom of the lock walls, and 66 have been extended to a depth of 50 feet or more below sea level. On the site of the proposed spillway 36 test bore holes have been put down, covering the whole area to be included by the controlling gates on the walls. All of these 36 borings extend to or below sea level and indicate a good and sufficient foundation in soft rock. We have now completed three parallel lines of test bore holes, 63 in number, across the whole width of the valley of the Chagres to be closed by the dam, all of these extending down to rock, and all of them are what are known as dry holes. Pervious material, or material which can possibly be penetrated by water, has been found in only 4 of these 63 holes, and this only at depths of 200 feet below perfectly impervious soil. In other words, there is a 200-foot blanket of impervious soil found at these bore holes before any pervious material is encountered. At the site of the proposed locks at Pedro Miguel 10 borings, distributed over an area bounded by the lock walls, 2,000 feet long, have been bored to below the bottom of the lock walls, and all show that the foundations of these walls will be in rock of varying hardness and perfectly suitable for foundations. It is possible that some of these foundations at Pedro Miguel, if exposed to the heavy action of the weather, would wear away, and it would probably be necessary to cover the floor of the lock chamber with concrete, when, of course, it would be impossible for water, weather, or anything else to have any action upon it. One test pit which we are putting down at Pedro Miguel has just about reached the bottom of the lock walls, and we are in a firm blue soft rock somewhat like that found at Gatun, which is certain to make a firm foundation and a perfectly safe one. At Gatun the test holes which we are putting down 6 by 8 feet we are hardly able to excavate more than 1 foot per day of ten hours, and all of them have to be drilled and blasted. We are still in this rock material, and the test pits, so far as dug, both at Gatun and Pedro Miguel, indicate the same material as found in the bore holes, excepting that in the test pits this material is harder than as indicated by the small cores which were taken out of the bore holes. I do not know that I can give any more information than to answer your request and further add that the results of our continued ex plorations only confirm my previous judgment that we have ample, sufficient, and perfectly safe foundations at all lock sites; and were I personally paying for the canal, I would have no hesitancy in recommending in strongest terms the construction of the locks on the sites selected. Truly, yours, Mr. T. P. SHONTS, JOHN F. STEVENS, Chairman Isthmian Canal Commission, Washington. ISTHMIAN CANAL. COMMITTEE ON INTEROCEANIC CANALS, 1907. Washington, D. C., Tuesday, February 12, The committee met at 10.30 o'clock a. m. Present: Senators Millard (chairman), Kittredge, Hopkins, Ankeny, Carmack, and Culberson. Present, also, Hon. William H. Taft, Secretary of War; Theodore P. Shonts, esq., chairman of the Isthmian Canal Commission, and R. R. Rogers, esq., general counsel of the Isthmian Canal Commission. STATEMENT OF R. R. ROGERS, ESQ., GENERAL COUNSEL OF THE ISTHMIAN CANAL COMMISSION. Senator KITTREDGE. As I understand, Mr. Rogers, the authority to make this contract is based upon section 5 of the Spooner Act? Mr. ROGERS. Yes. Senator KITTREDGE. And that reads as follows: SEC. 5. That the sum of ten million dollars is hereby appropriated, out of any money in the Treasury not otherwise appropriated, toward the project herein contemplated by either route so selected. And the President is hereby authorized to cause to be entered into such contract or contracts as may be deemed necessary for the proper excavation, construction, completion, and defense of said canal, harbors, and defenses by the route finally determined upon under the provisions of this act. Appropriations therefor shall from time to time be hereafter made not to exceed in the aggregate the additional sum of one hundred and thirty-five millions of dollars, should the Panama route be adopted, or one hundred and eighty millions of dollars should the Nicaragua route be adopted. Since that time there has been appropriated $10,000,000 to pay the Republic of Panama for the rights we acquired from that Government; in December, 1905, $11,500,000, as I recollect; about April, 1906, a further sum of $5,000,000; and in the sundry civil bill a further sum of $25,000,000 was appropriated. Have I the figures accurately in mind? Mr. SHONTS. That is my recollection. Mr. ROGERS. That is fifty-one millions and a half. Senator KITTREDGE. Yes. One point I would like to have you take up (taking your own time to speak of it) is, What authority, if any, has the Commission to enter into a contract where the amount to be paid by the Government exceeds the sum of $135,000,000, less the $51,500,000? Mr. ROGERS. The total appropriation is $145,000,000, including the $10,000,000 originally appropriated in section 5, which you have read. Senator KITTREDGE. This section 5 authorized the appropriation of $135,000,000, in addition to the $10,000,000. Mr. ROGERS. Yes; making $145,000,000 altogether. |