OBSERVATORIES AND THE DATA OBTAINED. 73 
MIZUSAWA, JAPAN.’ 
Meteorological Observatory. 
Lat. 39° 08’ N.; long. 141° 07’ E.; distance, 70.46° or 7,834 km.; chord, 7,349 km.; 
direction, N. 55° W. 
The instrument used was an Omori horizontal pendulum; mechanical registration on 
smoked paper. 
First preliminary tremors, 24" 07°; interval, 11™ 39°. 
Second preliminary tremors, 33" 14°; interval, 20™ 46°. 
Apia has a Wiechert pendulum which magnifies more than the Omori at Mizusawa 
and therefore probably showed the movement more promptly. 
PONTA DELGADA, AZORES. 
Servigo Meteorologico dos Acores. Major F. A. Chaves, director. 
Lat. 37° 44’ N.; long. 25° 41’ W.; altitude, 16 meters; distance, 72.53° or 8,064 km.; 
chord, 7,536 km.; direction, N. 55° E. 
Foundation, basaltic rock in a volcanic region. 
Seismograms, sheet No. 1. 
The instrument used was a Milne horizontal pendulum, east component; photographic 
registration. V, 6.1; angular displacement, 1 mm. = 0.49”; M, 255 gm.; L, 15.6 cm. 
First PRELIMINARY 
TREMORS. 
Principat Part, . AMPLITUDE. 


; min, min, 
East component. . 23.6 50.5? 
Interval .. Hi 38.0? 



Duration, 3.5 hours. The second preliminary tremors are not distinguishable. There 
is a curious difference between the seismograms of Ponta Delgada and those of Paisley 
and Edinburgh, at practically the same distance from the origin. In the former, the first 
preliminary tremors are stronger and the beginning of the second preliminary tremors 
are not clearly differentiated; in the two latter, the first preliminary tremors are very 
feeble but the second preliminary tremors begin sharply. 
PAISLEY, SCOTLAND. 
Coats Observatory. David Crilley, director. 
Lat. 55° 51’ N.; long. 4° 26’ W.; altitude, 32 meters; distance, 72.54° or 8,065 km.; 
chord, 7,537 km.; direction, N. 31° E. 
Foundation, boulder clay. 
Seismograms, sheet No. 1. 
The instrument used was a Milne horizontal pendulum, east component; photographic 
registration. Jo, 17 seconds; V, 6.1; J, 440 meters; angular displacement, 1 mm. = 
0.55”; M, 255 gm.; L, 15.6 cm. 





ee ern aeiltasann| aba, |) Mas |Aueucronn, 
min. min. min, min. min, mm, 
East component . 23.2 sare 47.4 51.0 to 0.0 | 54 to 57 17 + 
Interval. . . 10.7 20.8 34.9 38.5 

Duration, 4.1 hours. The period of the long waves was from 25 to 30 seconds. 
1 Information obtained from “Preliminary Note on the Seismographiec Observations of the San 
Francisco Earthquake,” by F. Omori, Bull. Imperial Earthquake Investigation Commission, vol. 1, 
No. 1. 
