120 KEPOET— 1892. 



The tensile strength of brick and mortar work from cotton-factories 

 and other private buildings seldom exceeded 5 lb. to the square iucb. 



Professor Tanabe, of the Imperial College of Engineering, has very 

 kindly applied the fracturing formula to the Kisogawa and other structures, 

 with the following results : — 



The tall piers at the Kisogawa Bridge, which were broken, were 

 capable of resisting an acceleration of 505 feet per sec. per sec, whilst 

 the shorter piers, which were also broken, could have resisted a force in- 

 volving an acceleration of 10'8 per sec. per sec. 



The acceleration in the neighbourhood of this bridge was therefore 

 greater than the higher of these two numbers ; because there is no 

 necessity that one set of piers out of a series should only have half the 

 strength of another group in the same series, or that any given structure 

 should be weaker at its base than it is in its upper parts. So far as resist- 

 ance to stresses consequent on horizontal movement is concerned, the 

 writer ventures to express the opinion that when constructing in an 

 earthquake country, ordinary engineering practice requires modification. 

 Such modifications are being made by Mr. C. A. W. Pownall in the con- 

 struction of a series of bridges now being built up the Usui Pass, in this 

 country. 



For the Nagara Bridge, where cast-iron j^iers have snapped in two, 

 the accelerations experienced have not yet been calculated. 



Leaving the railway works, and examining the various brick-and- 

 mortar structures, like public buildings and mills, which existed at many 

 towns upon the plain, we meet with hardly anything but absolute ruin. 

 Two conspicuous brick-and-mortar ruins in Nagoya were the Post Office 

 and a cotton-mill. Walls like these, even if not weakened by openings 

 near their base, assuming them to have been 40 feet high and 1^ foot 

 thick, and with a tensile strength for their brickwork of 5 lb. per square 

 inch — which is not an underestimate — might have resisted a suddenness 

 of motion of a few inches per sec. per sec. From overturning phenomena 

 and diagrams we know the acceleration impressed upon buildings in this 

 area may have been as much as 15 feet per sec. per sec. 



One curious form of destruction was that which was observed with 

 many mill chimneys, which, with the exception of one in Yokohama, in- 

 stead of breaking at their bases, gave way at about two-thirds their 

 height. Sections near the bases of these chimneys were apparently 

 sufficiently strong to resist the stresses due to the inertia of the upper 

 parts, while sections at about two-thirds the height were so weak that 

 they failed to resist the inertia effect of the upper one-third of the 

 chimney. Calculations respecting these structures have not yet been 

 made. 



The ruins of ordinary Japanese buildings existed along all the roads 

 in never-ending lines. In some streets it appeared as if the houses had 

 been pushed down from the end, and they had fallen like a row of cards. 

 Where a row of buildings had only been partially pushed over, it was 

 noticeable that those at the end had suffered more than their neighbours. 

 Sometimes you passed acres of heaped-up rubbish, where sticks and earth 

 and tile were so thoroughly mixed that traces of streets or indications of 

 buildings had been entirely lost. 



Many of the ruined towns, like Kasamatsu and Gifu, caught fire, and 

 all that remained was a sea of reddish earth and broken tile. At several 

 places people were caught in the fallen ruins, and subsequently burnt ta 



