the bridge into bits that could be handled. These experiments brought out the fact that there were just two means at hand, one being dynamite, the other the oxy-acetylene flame. Each was peculiarly adapted to certain conditions, so that each supplemented the other. Together they have performed feats not matched in the annals of engineering. Dynamite worked particularly well under water. One stick of the explosive would break a plate half an inch thick, while to break a plate an inch thick two sticks were required. In order to cut one of the great girders, sticks of dynamite were placed end to end across it, usually tied to a stick of wood or placed in a piece of cheap rubber hose. If the cut was to be done on the water the explosive was placed in position at low tide. Then the workmen waited until the tide rose, thus affording a water tamping. Above high water the charge was covered with a few inches of earth. Extra precautions had to be taken in seeking shelter when a charge was to be fired, for pieces of steel were thrown great distances. One piece was thrown across the river. Twelve tons of dynamite were used in breaking up the south anchor arm. the caisson, a solid block of concrete 150 feet long, 49 feet wide and 25 feet deep. This is to be pieced out by an L-shaped extension to be formed of two caissons, one 25 by 31 feet, the other 31 by 85 feet, which are to be sunk to the same depth as the old one this spring. On top of the extended foundation a third caisson 180 by 79 feet and 27 feet high, to be of solid concrete strongly reinforced with steel, will be built, upon which the masonry will be erected. As the river span is to be shortened forty-two feet, the north main pier will be nearer the river and entirely clear of the old. For the foundation of this pier a caisson of unusual size was built. Some idea of the magnitude of the undertaking may be gathered from the fact that two hundred thousand dollars were expended on a plant for building the great caisson and the smaller ones for the south pier. The north caisson, 180 by 55 feet, was built of timbers 12 inches square and solidly braced by dividing the interior into eighteen working chambers, each 20 by 25 feet, with heavy timber walls. By the time the outer walls had been built up to a height of 21 feet 9 inches and the total weight was 1,700 tons it was deemed ready for launching. The Oxy-acetylene gave remarkable re- remainder of its 68 feet in height was sults. It was used to greatest advantage to be built up as sinking proceeded. in cutting the heavy chords and posts The launching took place July 7, 1910, into pieces. The flame cut very rapidly, and the big box was towed three miles. leaving a narrow, sharply defined slot up the river to the bridge site. Unfornot wider than a saw would make. A tunately it sprung a leak after the work square inch of steel could be cut through of sinking had begun and the pumps in 55% seconds with 0.4 of a foot of gas breaking down, it filled and sank on the costing 1.2 cents. An eyebar 2 inches big boulders in the river bottom in such thick and 10 inches wide was cut through a position that it was strained. So it had in one minute and fifty seconds with the to be laboriously floated and towed to a flame. This method proved very con- dry dock for repairs. To gain time a hole venient, for as the torch weighs but a twenty feet deep was dredged on the few pounds it could be carried around pier site, leaving just that much less anywhere. When ten of the sixteen excavating to be done under compressed months had elapsed but half the wreck- air in the caisson. A boiler plant of six age had been removed. The contractor, hundred horse-power was required to who gets $45,000 and the scrap, doubt- furnish steam to run the compressors less feels that he is earning his money. in sinking this caisson. As the new bridge is to be wider, shorter and heavier than the old, the original piers could not be used, although the masonry was unharmed. The foundation of the old south main pier, however, was all right so far as it went. So If everything goes as it has been planned the masonry work on the piers will be finished by November 1, so that the erection of the superstructure may begin as soon as the weather will permit in the spring of 1912. By 1915 trains 'N Palestine the native horseshoer, known as a "betar," not only shoes but also treats sick animals, corresponding in this latter respect to our veterinary surgeon. His shop is invariably a very small concern, unlike anything found in the Occident. In the first place, there is no blacksmith work done of any kind, hence, no fire or forge. Two methods of shoeing are followed, one known as the native and the other as the European. The native shoes are solid plates, covering the entire hoof, with a small air-hole in the middle, and curving outwards at the back. Those Those known as European are very similar to our American shoes. The assistant holds the animal's leg up when the farrier, or shoer, in a halfkneeling position, removes the old shoes. with a pair of large pincers, the jaws of which are very dull. The trimming or cutting of the hoof is done with a draw knife, the blade of which is six inches long and four inches wide, very sharp and thin. The shoes are fitted cold, and as soon as they are placed upon the feet, a curious little wooden block is brought into play. Upon this the animal is made to place one foot at a time while the farrier drives home the nails. These latter protrude about half an inch or a little more. The inside ones are cut off, turned over and clinched into the hoof, while the outside ones are curled around and around by being lightly tapped with a hammer. In a dry and stony country like Palestine native shoes have these advantages over European ones: stones cannot get into them, while the hoof being practically entirely covered keeps moist and much softer, making the liability of cracked hoofs quite remote. The native shoes are made from thick sheet iron and also from wrought iron. They are finished very roughly and require a good deal of hammering before. they are ready for use. The European shoes are finished ready to be put on. In Jerusalem there are only two European blacksmith shops doing European shoeing. One is run by Germans and the other by an Armenian, who learned the trade from the Germans. They are mostly patronized by foreigners. The natives have a prejudice against burning the hoofs with the shoe. Less than half a century ago European-shaped shoes were entirely unknown in Palestine. The first horse shod in this manner was that belonging to the Russian consul some thirty-nine years ago. |