( 410 ) 



(lie liill-i';iii,ut' i-iuli;iliii,ii' iioi'tliwjird IVoin Sopoctjiii ; Imt l>_v dijing su 

 we are jA'oiiiii' slill tartlier aslrav in llie daiigerous lield ofcoiijeciiire 

 vvitliout even having tlie support of chronological data. 



The sending out of an apophysis by a hearth of magma will be 

 hardly conceived otherwise than along a newly opened fissure, or 

 by the sudden widening of an existing fault, both facts which, 

 according to the <Mirrent views, may be causally connected with 

 earth-quakes, so that we need not look any further for the primordial 

 cause of the series of volcanic and seismic ])henomena. I must re|)eat 

 here howevei', that the composition of the earlli(piakes in the Mina- 

 hassa for the lirsl half year of 11)01 in the appended table A does 

 not reveal such connection with any certainty. 



We succeed still less in discovering for 190() any co-relal ion between 

 the volcanic and the seismic events in the Minahassa. At the time 

 when the out-bi-eak began, the region was, as appears from tlie 

 composition A, in a state of seismic calm which continued for almost 

 four months, and the fact that the oidy earth-motion between April 29 

 and August '22 took place on the very day that the break-out began, 

 loses all further value, because tliis shock was of no greatei- sigjuti- 

 cation than the slight pnlsations that repeatedly occur here ever and 

 anon also nnder ordinary circumstances. 



It is quite different in 1907. The month of June in which the 

 crater of 190(i resumed its activity shows, with (i earthquakes in 

 about 20 days, a rather high frequency, whilst the most violeut 

 shock, abont mid-night of 25 to 26, with an intensity of Vll U) \T11 

 (Rossi-FoREi,) at Tomohon ^), Tondano and Menado"-), was followed, 

 as also observed on the spot, by a strengthening of the volcanic 

 action. Consequently we are fully entitled to regard this pulsation 

 as a real volcanic one, and then it is not nnimportant that it has 

 also been recorded at Batavia. Besides this surely not accidental 

 coincidence, the recognisable connection is restricted to an increased 

 freqnency of eai'thquakes especially in June. As long as the move- 

 ments of volcanic origin cannot systematically be separated from the 

 real bathn-seismic commotions nothing more may be expected. 



As appears from the comparative synoptical table B such a more 

 or less evident coincidence of greater seismic agitation in the Mina- 

 hassa" and increased or renewed activit}' of not too far removed 



^) "Coins lying on the table slid down: clocks stood still; the water spurted 

 "out of the ewers. Rumbling before and after the shock. The violent shock was 

 "followed by three lighter ones In the neighbouring Tondano the church-bell began 

 "to toll by the shaking of the earth."' (Communication of Mr. A. LimbukgI. 



-) "Trees were distinctly seen to swing, hanging lamps oscillated more than 

 "0,5 M. out of the perpendicular (pendulum-length ± 2V2 M.)". Amplitude conse- 

 "quently + 2:2°. "Fissures in walls". (Communication of Mr. F. A. J. Keuchenius). 



