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PANAMA

ordered him to repudiate the interview, in which he was quoted as saying this and he afterwards expressed in person to the President of Panama his regret for having misunderstood his duty and offered an apology. He was later recalled. The United States government authoritatively denied that it contemplated annexation before the opening of the Panama Canal, pointing to the clause in the Hay-Varilla treaty declaring that the United States guarantees the independence of the Republic of Panama. On September 14 the Assembly, which was controlled by the Liberal party, voted almost unanimously for Pablo Arosemena as first vice-president (designado), to serve as acting president for the unexpired term (ending October 1, 1912) of the late President Obaldía. For second vice-president, Federico Boyd was chosen, and for third, Rodolfo Chiari. The estrangement between Panama and Colombia showed a prospect of coming to an end in 1910, when Panama sent Dr. Carlos Mendoza on a mission to Colombia, but the mission was later reported to be unsuccessful.

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PANAMA CANAL. Work on the canal progressed steadily through 1910 without serious hindrances of any sort. The total amount of excavation and a comparison with the excavation of 1909 will be found in the accompanying table. The year was notable for the marked absence of criticism of the plans and performances of those in charge of the work. The movement, which originated in the latter part of 1908 and continued during the early part of 1909 against the lock canal, and for a water-level canal subsided, and there was no revival of this criticism in 1910. In November visits were made to the canal by President Taft and by a party of .engineers representing the American Institute of Civil Engineers. The President expressed great satisfaction with the progress of the work and the engineers were equally favorable in their comments and expressed the opinion that from an engineering standpoint the work could not be improved.

The organization of the Isthmian Canal Commission remained the same during 1910, except that Hon. J. C. S. Blackburn, who resigned on December 4, 1909, was succeeded by Maurice H. Thatcher on April 12, 1910. By an executive order of April 16, 1910, the position of counsel and general attorney was created. Among minor changes made in the organization was the abolition of the mechanical division as it formerly existed, and the work formerly done by the division was distributed among the different shops in the Canal Zone. An inspector of shops was added to the organization with the duty of looking after the economical distribution of work among the different shops, the distribution of tools, besides the additional shop facilities and the adoption of standard shop methods. A standard wage scale for employes on the gold roll was adopted and put into effect. After its adoption the heads of departments and divisions fixed a maximum limit of pay for the various positions considered by them as necessary for the proper conduct of the work in their charge, and the pay of positions on the gold roll is now standardized, no variation being allowed except in cases where increased responsibilities and duties fall upon its occupant.

The work of the canal is divided into four divisions. The First Division, which is charged with the design of the locks, dams, regulating works and accessories, is in charge of Lt. Col.

PANAMA CANAL

H. F. Hodges of the Corps of Engineers, U. s. Army. The Atlantic Division has charge of construction work, which is divided into four parts: First, that comprising the excavation of the channel between the Gatun locks and the Atlantic Ocean; second, the construction of the Gatun locks; third, the construction of the Gatun dam and spillway; and fourth, the municipal engineering work. This division is in charge of Lt. William L. Siebert, Corps of Engineers, U. S. Army. The work of the Central Division includes excavation in that part of the canal which embraces the entire extent of the former Culebra and Chagres sections of the Central Division. It is in this division that the greatest amount of excavation work is done. The division is in charge of Lt.-Col. D. D. Gaillard of the Corps of Engineers, U. S. Army. The Pacific Division includes the excavation and construction for a distance of 11 miles from Pedro Miguel to deep water in the Pacific Ocean. It is divided into four districts: First, locks, dams and dry excavation; second, dredging, hydraulic excavation, Balboa shops and shopways; third, municipal and sanitary work; fourth, Ancon quarry. This division is in charge of S. B. Williamson.

FIRST DIVISION. During the year detailed drawings for the upper lock at Gatun and for the single lock at Pedro Miguel were made and the general features of the lower locks at Gatun and the lock flight at Miraflores were adopted. These general features include the use of intermediate gates in the middle and lower locks at Gatun, but of no intermediate gates at the lower lock of Miraflores. The south approach wall at Pedro Miguel was designed of massive concrete and the larger part of it is constructed. The northeast wing wall will also be of massive concrete, and reinforced concrete walls have been designed for the northwest, southeast and southwest wing walls in the same locality. During the year general and detailed drawings for all the gates required fully to equip the locks were completed and bids were issued. The lowest bid was that of the McClintic-Marshall Construction Company of Pittsburg, Pa. This was accepted and a contract made with this firm. The advertisement called for the erection complete of all the gates of the canal, 46 in number or 92 leaves, by January 1, 1914. The contractors bind themselves to complete the work by January 1, 1913. In the contract the work of erection at Gatun is to begin on January 1, 1911, and to be completed on February 1, 1913; at Pedro Miguel the work of erection is to begin March 1, 1911, and to be completed May 1, 1912; and at Miraflores work is to begin January 1, 1912, and to be completed June 1, 1913. Much study has been given by the engineers of the commission to the question of the machinery for operating the gate leaves. As the result, the recess in the wall into which the leaf fits when open was modified so as to admit of freer exit of water around the mitre post when the gate is near the position of rest, and a type of machine was adopted in which the force applied increases and the rate of motion decreases near the beginning and end of the movement. The machinery adopted consists of a rigid horizontal strut connected to the upper girder and the gate leaf. The other end of the strut is attached to a large horizontal gear wheel near its circumference. As the large gear wheels turn the effect of the strut is practically that of a crank pin on a connecting rod. The

rate of travel of the gate increases gradually from the beginning to a point just beyond the middle of the path between the recess and the mitre. After passing its maximum the rate gradually diminishes until just at mitring it becomes very small. It has been thought desirable to provide all the gate leaves with a positive lock which will hold them together against wave action and at the same time it has seemed possible to arrange a locking device which will force the gates to meet perfectly at the mitre, thereby reducing the care which is usually necessary in closing large lock gates to avoid a false mitre. The general plan of the machinery to be used in the raising and lowering of the gates on the crest of the spillway dam at Gatun has been prepared. The machinery has been mounted in a tunnel in the main body of the dam for the purpose of protecting the parts of the machinery and the counterweights, this arrangement at the same time obviating the installation of cumbersome and heavy material on the foot bridge which extends over the gates. Designs have been prepared for an electric locomotive which, it is thought, will prove satisfactory to tow vessels through the locks and have full control of them from the time they approach until they are locked through to a point from which they can proceed under their own steam.

Investigation of the expenditure of water from Gatun Lake as affected by the design adopted for the locks was carried on during the year. The results indicate that during ordinary years there will be a surplus of water even during the dry season, and that the water supply of the worst known dry season for the last 19 years, that of 1908, will be sufficient to maintain through the canal an average daily number of passengers three or four times as great as the average num ber now passing through the Suez Canal.

ATLANTIC DIVISION. The work of excavating the locks was continued in 1910 by steam shovels and to some extent by dredges, resulting in the removal in lock chambers during the year of 3,965,699 cubic yards in the dry, and 435,178 cubic yards in the wet. In addition to this excavation there were removed 646,520 cubic yards of material in auxiliary work, including dredging in the French canal. The excavation in the upper locks was completed. The excavation for the lower locks, exclusive of the approach walls, was undertaken, and but 375,000 cubic yards remained to be removed at the close of the fiscal year. During the fiscal year there were laid in the Gatun locks 513,083 cubic yards of concrete. The total amount of concrete to be placed in the locks, including the approach and wing walls, is estimated at 2,046,100 cubic yards, so that the total amount remaining to be placed at the end of the fiscal year was 1,532,297 cubic yards. With a view to reducing the cost of concrete, instructions were issued to make arrangements to embed large stone, not less than oneman size, in the masses of concrete, which would amount to about 20 per cent. of the mass. This was begun in March, 1910, and up to the close of the fiscal year aggregated a total of 10,786 cubic yards.

At the Gatun Dam prior to January, 1910, the operations in the construction were practically limited to that portion between the locks in Spillway Hill. In the latter month it was decided that a larger amount of material for the toes of the dam should be procured from the Central Division, this supply to be utilized as long

as it could be economically furnished. At the close of the fiscal year the north and south toes of the portion of the dam east of Spillway Hill had reached an elevation of 65 feet above mean tide and the hydraulic fill between the toes an average elevation of 51 feet. West of Spillway Hill the north toe had been carried to an elevation of plus 30 feet and the south toe to an elevation of plus 35 feet. The total amount of material placed in the dam during the fiscal year was, dry fill, 2,577,234 cubic yards, and hydraulic fill, 2,933,175 cubic yards. Trestles aggregating 7486 cubic feet were constructed during the year. Excavation for the spillway was continued during the year, resulting in the removal of 127,210 cubic yards. The excavation for the foundation of the spillway dam was completed except at the extreme end and that for the curtain and side walls and for the floor was fully completed. By April 25 the side walls, floor and curtain walls were completed and the foundation of the dam sufficiently advanced to warrant turning the Chagres River through the spillway. Considerable time was lost owing to the excessive floods of November and December, 1909.

Excavation in the dry in the channel between the Gatun locks and the Atlantic Ocean was continued until November 20, 1909, when work was suspended due to the cut being filled by the high water in the Chagres River which had access to the French Canal. There were cavated in the dry, 991,572 cubic yards of earth, and 233,144 cubic yards of rock. The deepest part of the cut had reached a depth of 42 feet below sea level at the time work was pended.

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CENTRAL DIVISION. The work on this division embraces all the excavation between the Gatun dam and Pedro Miguel locks, including diversion channels, construction of the Naos Island breakwater, clearing of timber from the channel and anchorage basin, municipal improvements in the various settlements included within the division limits and such sanitary engineering work as is prescribed by the sanitary department. In this division is included the famous Culebra cut. The total excavation in this division during the fiscal year 1910 was 17,865,808 cubic yards, which was something more than 2,000,000 cubic yards less than the amount excavated in the fiscal year 1909. It is estimated by the engi neers that the total amount to be excavated from this division is 38,309,475 cubic yards.

From the Culebra cut 14,921,750 cubic yards were excavated during the fiscal year, leaving 34,893,531 cubic yards to be removed in order to complete this section of the canal. This also includes an increase of 6,408,560 cubic yards over the estimate made in September, 1908. This increase is due to the widening of the canal north of Pedro Miguel lock so as to form a basin, and to allowance made for slides and breaks, as a number of new ones developed during the year and could not be foreseen when the estimates of 1908 were made. These slides and breaks are the chief obstacles with which the engineers have to contend in making the excavations in this cut. Four large slides occurred prior to 1910 and these made it necessary to remove over 1,000,000 additional cubic yards of excavation. Three bad breaks occurred during the fiscal year 1910. On the west bank of the canal at the town of Culebra the break covers an area of 10% acres and during the fiscal year 1,500,388 cubic yards were

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PANAMA CANAL. GENERAL VIEW OF UPPER LOCKS AND FOREBAY AT GATUN, LOOKING NORTH, JULY, 1910

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