106 REPORT OF THE CALIFONRIA EARTHQUAKE COMMISSION. 
time of arrival of the regular waves is doubtful; at the time given there is a change in 
the general character of the record, the irregular phase becoming more regular and the 
amplitude larger. The friction alters the magnifying power very materially; in the 
absence of precise knowledge of its value we can not estimate the earth’s amplitude. 
BATAVIA, JAVA. 
Royal Magnetic and Meteorological Observatory. Dr. W. van Bemmelen, acting 
director. 
Lat. 6° 11’ 8.; long. 106° 50’ K.; altitude, 3 meters; distance, 124.99° or 13,897 km. ; 
chord, 11,300 km.; direction, 8. 112° W. 
Foundation, alluvium. 
Seismograms, sheet No. 15. 
The instrument used was a Rebeur-Ehlert horizontal pendulum, north component; 
photographic registration. T,,9.4 seconds; V, 65.5; J, 1,440 meters; ¢, 1.15; M, 200 
‘gm. (?); L, 12.2 cm. 


First Pre- Cigale Earta’s 
LIMINARY rear Max. PrEriop. AMPLI- 
E ls 
TREMORS Tasmond. TUDE. 


min. ; mm. 
North component... . .| 382 54{| 42 16 30.6 0.18 
Interval . . « = - » +») 20 26.) 20 348 | Gleo4 




The instrument was not still when the disturbance arrived; from an examination of 
the photographic copy of the seismogram it seems probable that the first preliminary 
tremors began at 29" 34", giving an interval of 17 minutes 06 seconds. During the 
regular waves an amplitude of 4.5 mm. was reached at 14” 17.5", when the earth’s 
amplitude amounted to 0.38 mm. This was the maximum earth movement. During 
the principal part at 14" 30.6", the earth-amplitude was 0.24 mm. 
KODAIKANAL, MADRAS, INDIA. 
Solar Physics Observatory. C. Michie Smith, director. 
Lat. 10° 14’ N.; long. 77° 28’ E.; altitude, 2,343 meters; distance, 127.96° or 14,226 
km.; chord, 11,449 km.; direction, N. 26° W. 
Foundation, directly on solid rock. 
Seismograms, sheet No. 2. 
The instrument used was a Milne horizontal pendulum, east component; photographic 
registration. T,,15seconds; V,6.1; J, 340 meters; ¢, 1.115; r,0.0mm.; M, 255 gm.; 
DL, 15.6 em. 
First preliminary tremors, 31.6" (?); interval, 19.1 minutes (?). Maximum, 28.8”. 
Amplitude, 2.5 mm. 
The position of this station has been misplaced on the map. It should be about 2 mm. 
from the southern point of India and equidistant from the sea, east and west. 
PERTH, WESTERN AUSTRALIA. 
Astronomical Observatory. W. Ernest Cooke, M.A., F. R. A. S., government astrono- 
mer. 
Lat. 81° 57’ S.; long. 115° 50’ E.; altitude, 59.5 meters; distance, 132.37° or 14,716 
km.; chord, 11,656 km.; direction, S. 78° W. 
Foundation, sand on limestones. 
Seismograms, sheet No. 2. 
