128 'TRANSACTIONS iSqQ-'oO 



the full number of quakes we have recorded in Toronto and 

 Victoria, I shall ask you to observe the seismograms for the 24th 

 January, 1898. In response to a letter which I wrote to the 

 Director of the Observatory in the City of Mexico, he wrote me 

 that two shocks of earthquake were recorded in Mexico on 

 January 24th, the first at 5.29 a.m., and the second at 5.9 p.m., 

 the first being slight and the latter strong. The earthwaves caused 

 by both of these quakes were recorded in Toronto and Victoria, 

 B. C. I shall not show you the seisniogram of the first as it was 

 comparatively small, but will show you the second. Prof. Milne 

 thinks that the time of the origin of the quake was two minutes 

 earlier than in Mexico; if so, we have Greenwich time at origin 

 I ih 43m 3 IS, beginning or preliminary tremors 6m 53s later in 

 Toronto, and 7m 36s later in Victoria, or about a velocity of eight 

 kilometers per second in both cases. The larger waves reached 

 both Victoria and Toronto between 22m and 23m after the quake 

 occurred, travelling at a rate of about 2.5 kilometers per second. 

 This quake was also recorded at the Isle of Wight, Kew Obser- 

 vatory, in Russia, Italy, Trieste and Bombay ; and all stations 

 agree that the time of the arrival of the larger wave gives a 

 velocity of about 2.5 kilometers per second measured on the arc. 

 On 7th March the seismographs recorded a Japanese quake of 

 much severity, the time of transit of the long waves was as fol- 

 lows : Isle of Wight 59m, Kew 59m, Rocca di Papa in Italy 

 56m, Toronto 65m, Trieste 47m. 



A point of interest in these seismograms is that the tremors 

 as recorded in England were greater than at Toronto, and at 

 Toronto they were greater than at Victoria, the station nearest to 

 the origin. This latter place would be reached by a path entirely 

 beneath the Pacific, Toronto by a path crossing Behring Straits, 

 and Shide (Isle of Wight), by a path across Asia to Europe. 

 Such records suggest that oceans exert a damping effect upon 

 the earth waves traversing their beds. 



Many quakes followed during the next three months, but we 

 will pass on to June 8th. There were two shocks recorded on 

 this day, and there is strong reason for supposing that the origin 

 was in the West Indies, east of Jamaica. The times were as 

 follows : 



