226 



REPORT — 1893. 



Earthquakes — cotitinued. 



Note. — The reason that the diameter of the area shaken by many shocks is given 

 as three miles is because the shock was only recorded at one place, and from inves- 

 tigations on areas disturbed by small shocks this number may be taken as approxi- 

 mately correct (see ' On a Seismic Survey made in Tokio,' Trans. Seis. Soc, vol. x.). 



Overturning and Fracturing op Masonry and other Columns. 



Tn tlie Twelfth Report (1892) it was stated that the form of a wall or 

 pier which, rather than snapping at its base, would, when subjected to 

 horizontal reciprocating motion, be as likely to snap at any one horizontal 

 section as at any other had been determined. 



A brick building with walls approximating to this form has been 

 designed and built by Professor K. Tatsumo on the Univer.sity com- 

 pound. Mr. 0. A. W. Pownall, M.I.C.E., has constructed brick piers 

 for the bridges on the Usui Pass, some of which are 110 feet high with 

 similar sections. 



An experiment relating to overturning which is in progress is to 

 determine the relationship between the dimensions of a body and the 

 amplitude of motion which will fail to overturn the same, no matter how 

 short the period of motion may be. 



Publication of a Seismological Journal. 



In consequence of many persons who took an active interest in 

 seismology having left Japan, because work which formerly found a place 

 in the publication of the Seismological Society now finds a place else- 

 where, and for other reasons, the Seismological Society, which between 

 1880 and 1892 had published sixteen volumes, ceased its existence. As 

 a certain amount of work still continues in order to bring this before 

 those who are interested in seismology, a seismological journal has been 

 published and the first volume already issued. 



