162 



REPORT — 1897. 



than that at Strassburg, or else that between the Strassburg isoseist and 

 the Isle of Wight, motion was propagated at only a little over 1 km. per 

 second, which, it may be noted, is a rate of transmission often observed 

 over short ranges near to an epicentre. An inference to be derived from 

 this is, that for purposes of comparison it is desirable that all stations 

 should be furnished with instruments of equal sensibility. 



If we accept the Strassburg record of the arrival of the first tremors as 

 correct, then the average velocity of propagation from Japan to that place 

 exceeded on the arc 18 kms. per second, whereas the average of very many 

 other observations on the same path have yielded apparent velocities of 

 half this quantity. 



The origin of this disturbance was along two almost north and south 

 lines in the middle of North Nippon. It may be taken as lying to the 

 north and south of a point in 140° 50' E. long, and 39° 40' N. lat. 



The times at which the shock was automatically noted at various towns 

 were in local time as follows : — 



H. M. s. 

 Miyako . . . . ' . . . . 5 8 55 P.M. 



Awomori 5811 



Yamagata 580 



Ishimaki 5 8 10 



Tokio 5 9 33 



The distance between Tokio and Yamagata is about 150 g.m., and 

 Tokio and the origin 240 g.m. Between the first two places the time 

 taken for the vibration to travel was 90 seconds, indicating a velocity of 

 about 10,000 feet per second. Assuming this to be correct, then the time 

 taken from the origin to Tokio would be 2m. 44s., from which it may be 

 concluded that the shock originated at 5h. 7m. 9s., or, in G.M.T., August .30, 

 20h. 7m. 9s. 



The times at which the commencement of this disturbance was noted 

 in Europe were as follows : — 



H. Jl. s 



Shide 20 23 6 



Strassburg 20 17 50 



Ischia 20 20 30 



Rocca di Papa (p. maximum by a horizontal pendulum) . 21 3 50 



., ( „ „ 7-metre „ ) . 20 55 



( „ „ 15 „ „ ) . 20 41 15 



Rome 20 21 15 



Catania, N.E.-S.W 20 25 24 



S.E.-N.W 20 21 4» 



Nicolaiew 20 7 30 



Time of origin in North Jf;pan . . . . . . 20 7 9 



Omitting the observations at Rocca di Papa and Nicolaiew, the fol- 

 lowing velocities have been determined : — 



