C bsei-vations 

 en Marginal 

 Vibration. 



Kerosene 

 Jjani]!. 



322 S. SEKIYA 



on the recent occasion. At the University, ^vhere tlie ground is hard 

 and firm, the seismogra|)h recorded only 8 mm. horizontal motion, as 

 compared with 21 mm. registered by a similar instrument placed on 

 soft soil a mile distant. ïotsuka is a small town, with a single long 

 street running along the foot of a hill; one side of the street, however, 

 is built on made-up ground. Most serious damage was done on that 

 side, while the opposite houses suffered very much less, though not 

 more than twenty feet distant. Houses built on cliffs and hill-brows 

 received more damage than those situated at the base or on the flat 

 summits of the same hill. To observe the effects of marginal vibra- 

 tion, the writer recently placed one seismograph at the steep edge of 

 a loamy hill 38 feet in height, and another similar instrument at its 

 foot. The motions, thus far measured, at those two levels are found 

 to be in the ratio of 2 to 1. A third instrument will shortly be 

 set up on the flat summit of the same hill. Observations of a similar 

 nature, on different rocks and at various heights, will form the subject 

 of a further paper. It is probably owing to marginal vibration that 

 houses on the Bluff of Yokohama are alwaj's heavy sufferers from 

 earthquakes. 



The extensive and rapidly increasing use of kerosene lamps in 

 Japan constitutes a grave danger in severe shocks. The lamps now 

 in common use are of very brittle materials, contain the most com- 

 bustible of oils, and are usually poised on ill-balanced stands. In the 

 great earthquake of 1855, at a time Avhem kerosene was unknown in 

 this country, fire broke out in Yedo at more than thirty points, 

 setting a very large part of the city in a blaze. In the event of 

 another such shock, the mischief which would be produced from this 

 cause alone is awfid to contemplate. Great credit will bo due to an}' 

 one who can invent a convenient earthquake safety-lamp, which, it is 

 to be observed, will also constiliite a valuable safeguard in ordinary 



