60 



PROCEEDINGS OF SECTION A. 



The largest number of disturbances recorded during any month 

 was in January, when 20 tremors were registered. November had 

 18 ; July and October, 17 each ; September, 15 ; April, 12 ; August, 10 ; 

 June, 9 ; March, 7 ; May, 6 ; February, 5 ; and in December for the 

 three days on which the machine was recording, 1 tremor was 

 registered. 



The following are the times of the various phases of the most 

 important tremors — those whose amplitude was over 5 millimetres : — 



Date. 



1911. 

 Jan. 3, 4.. 

 June 17.. 

 July 12 .. 

 Aug. 16, 17 

 Oct. 24 . . 



Pre- 

 liminary 

 Tremors 

 (Longi- 

 tudinal). 



h. m. 

 23 37-2 

 14 35-7 



4 15-8 

 22 44-7 



20-5 



2nd 

 Phase 

 (Trans- 

 verse). 



h. m. 

 23 50 

 14 52-7 



4 23-5 

 22 56-3 



26-2 



Dura- 

 tion. 



h. m. 

 7 44-3 

 4 91 

 4 50-2 

 4 28-3 

 1 32 



Remarks. 



1 mm. dis- 

 ■ place- 

 ment 



0-25 



1912. 



The record for 1912 did not commence until 15th February, on 

 which date the new recording apparatus was finally installed and 

 adjusted. From thence until 20th December, 113 tremors were 

 recorded, as follows :— 



During this year the greatest number of tremors were registered 

 in the month of March, when 26 were recorded. Next in order came 

 April, with 17 tremors ; May and August had 13 each ; July, 12 ; Feb- 

 ruary and June, 9 each ; September, 7 ; October and December, 3 ; 

 and November, 1. 



