i i 
ON SEISMOLOGICAL INVESTIGATIONS. 
Ct 
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Date Time at er Lat. and long. Remarks, 
1910 No. origin District in aeons F=felt, D=destructive 
Noy. 10*) 2579 | 12.11ca MV, 160 E. 0 N.S. 
saa 14*) 2585 | 7.33 BE, 120 BE. 21 N. | N. Formosa, F. 
4 15*| 2589 | 14.18ca L 16 W. 628 
Pa 24 | 2594 | 15.41ca F, 90 E. 6 N. 
i 25 | 2596b) 19.12 EK, 125 E. 6 N. S.E. Mindanao, Saran- 
gani Is., F. 
4 26*| 2598 | 4.39ca F, 167 E. 8S Not recorded at Shide. 
om 29*| 2599 | 2.24 E, 125 E. 25 N. | E. coast Formosa, F. 
Dec. 1 | 2601 | 15.42 F, 135 E.0 N.S. | About this time an 
earthquake was re- 
corded in Tondano 
in Menado. 
Rs 3 | 2603 | 4.5ca F, 155 EK. 48. | Namatani, New Ire- 
land, F. 
iS 3*| 2604 | 7.47ca F, 155 HE. 45. 
‘a 4*| 2606 | 11.0ca F, 140 E. 108. | About this time an 
earthquake was re- 
corded in Ambon. 
a 5 | 2609 | 16.21 E, 150 KE. 42 N. | Off N.E. Japan. 
e 10*| 2612 | 9.25 F, 159 E. 88. | Recorded in Ambon. 
bs 13*| 2620 | 11.34 O 33 E. 9S. or 
30 E. 7S. 
a 14*| 2622 | 20.27ca M, 176 BE. 10 N. 
ES 16*| 2624 | 14.45 BE, 125 E.5 N S. Mindanao, Saran- 
gani Is., F. 
oe 16 | 2625 | 18.50 E, 125 E.5 N. | 8. Mindanao, Saran- 
gani Is., F. 
3 17 | 2627 6.33 EK, 127 E. 4 N. N.E. Celebes. 
is 18 | 2629 2.42ca E, 127 EK. 4 N. N.E. Celebes, S. Min- 
danao. 
is 23 | 2639 | 0.29ca K, 150 E. 62 N 
es 26 | 2640] 5.34ca E, 149 FE. 18 N. 
s 27 | 2642 | 18.50ca E, 123 EF. 5 N 
a 29 | 2647 | 13.5 BE, 122 BE. 3 N Ambon and Mindanao, 
*) 30*| 2650 | 0.45ca E, 128 E. 8 N Mindanao, Samar, 
Leyte, Butuan, D. 
III. On the 443 or 452 Day Period. 
In the Report for 1912, p. 94, I pointed out that marked periods of 
rest followed groups of megaseisms every 443 days. Professor H. H. 
Turner increased this period to 452 days. December 14, 1899, is the 
middle of a rest period, and we find similar periods every successive 
443 days. ‘The last period—which, however, is only one of partial 
quiescence—was about September 3, 1909; we should expect the next 
one about November 20, 1910. The fact that the accompanying 
catalogue shows that between November 14 and 24 no large earth- 
quake was recorded verifies the expectation. 
IV. On the Determination of the Position of Epicentres. 
In the British Association Report, 1896, p. 230, I showed by 
example that the distance of an epicentre could be determined from 
the duration of preliminary tremors. In 1911 Prince Galitzin showed 
that not only could a distance be determined from these precursors, 
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