62 



PROCEEDINGS OF SECTION A. 



New South Wales shock, 18th January, 1913, which was strongly felt 

 in many places in the neighbourhood of Bega, Cooma, and Eden. 



I greatly regret that, owing to poor health, and my absence for 

 seven months in Europe on a seismological tour, the forwarding to 

 many land fellow workers of the detailed earthquake analysis, as well 

 as occasional photogram copies of more important seismograms, has been 

 unavoidably delayed. Detailed acknowledgments of their numerous 

 kind communications forwarded here will be sent out shortly. 



Adelaide Observatory. 



G. F. Dodwell, Government Astronomer for South Australia. 



seismology. 



The Mike Horizontal Pendulum Seismograph recording the EW 

 cornponent has been in continuous operation at the Adelaide Observatory 

 during the period covered by this Eeport, viz., January, 1911, to 

 December, 1912, a very small proportion of the registrations having 

 been lost, owing to the failure of the electric light, &c. 



The instrument has been described in a paper on South Australian 

 Earthquakes, read before the Association in January, 1909. 



Gradual changes of level of a seasonal nature have been recognised 

 in the records, and the level change has occasionally been rather large 

 and sudden, and it appears to be due on such occasions to heavy rains 

 affecting the foundations. 



The total number of distant earthquakes from 1st January, 1911, 

 to 31st December, 1912, whose maxima were greater than 2*5 mm. 

 was 35, 19 of these being in 1911 and 16 in 1912. 



The tabulated records of the seismograph are sent to Professor 

 Mihie for publication in the Annual Report of the Seismological 

 Committee of the British Association. 



A list of earthquakes originating in South Australia is supplied 

 herewith. 



