ON THE EARTHQUAKE AND VOLCANIC PHENOMENA OF JAPAN. 119 



motion, but in many places it was noticeable that the sleepers, relatively 

 to the ground, had been moved endways. Neither of these movements 

 greatly exceeded 6 inches. Wherever the line crossed a small depres- 

 sion in the general level of the plain, even if it did not exceed 2 or 3 feet, 

 at such places the whole of the track was bent from its straight course 

 into a bow-like form, suggesting the idea that along these depressions, 

 which are probably filled with softer material than that composing the 

 plain, a greater quantity of motion had been transmitted, which, striking 

 the line like a flood, had caused a permanent deflection. The more reason- 

 able explanation is that these lines of soft material, like the valleys and 

 river-beds, had been permanently compressed, and the amount of com- 

 pression was measured by the amount of bending. Effects of compression 

 were most marked on some of the embankments, which gradually raise 

 the line to the level of the bridges. On some of these the track was bent 

 in and out until it resembled a serpent wriggling up a slope. Not only 

 were there these horizontal foldings, but by subsidence or compression 

 there were vertical folds, which in places gave the line the appearance of 

 a switchback. Close to the bridges the embankments had generally 

 disappeared, and the rails and sleepers were hanging in the air like huo-e 

 catenaries. 



At the bridges, one of which, over the Kisogawa, and made up of 

 200-feet spans, is 1,800 feet in length, the destruction was various. In 

 neai'ly all cases wing walls had given way. At one brick bridge the abut- 

 ments had been forced backwards, and the arch had fallen bodily between 

 them down upon the roadway, where it lay in two big segments, looking 

 like a gigantic toggle-joint. At the Nagara Bridge the piers, each of 

 which consisted of five large iron columns filled with concrete and braced 

 together, had in several instances not simply been broken at their bases 

 but they were snapped in pieces and thrown out upon the shingle beach 

 of the river, where they lay like bits of broken carrot. The bridge 

 was thrown 19 feet out of a straight line, and one of the foundations 

 near the centre of the river moved 5 feet 2 inches up-stream. Where the 

 greatest deflections occurred the foundations could not be positively 

 recognised. 



Mr. 0. A. W. Pownall, who constructed these bridges, and who o-ave 

 me the above measurements, estimates the deflection on the line where it 

 approaches the bridges at 1 foot 6 inches in a distance of 90 feet. The dis- 

 tance through which the foundations of the Kiso Bridge have permanently 

 approached each other is 2 feet in a span of 200 feet — that is to say, the 

 contraction across the river-bed is 1 per cent. When all the piers of a 

 bridge had not been broken, it was observed that those which escaped 

 were the shorter ones, near the river banks. The longer piers of the 

 Kisogawa Bridge had a cross-section of 22-5 feet by 10 feet, and a heicht 

 of 29 feet above the plane of fracture, which was 4 or 5 feet above their 

 foundations. They carried girder's weighing about 200 tons. The shorter 

 piers, which also had a cross-section of 22'5 feet by 10 feet, had heights 

 of about 21 feet above their planes of fracture. They carried girders 

 weighing about 22 tons. 



The tensile strength of the brick and cement work of these piers was 

 as shown by actual tests, unusually high, often reaching 100 lb. to the 

 square inch. When making these tests, it was seldom that the cement 

 gave way, fracture taking place either by the breaking of the brick or by 

 separation between the cement and brick. 



