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can draw tlirougli tliose places on a map a co-seismic 

 line, and if tlie shocks travel at an equal rate in all directions, 

 the co-seismic lines will be circles, and of course places near 

 the centre of disturbance will feel the shock earlier than those 

 more remote. Further, if we can show that two places are 

 on the same line drawn from about the centre of disturbance 

 we ought to be able to demonstrate the ra,te at which the 

 vibration travels between the places. 



The times reported for the different shocks do not agree 

 very well, so that it is difficult to base any reliable conclusions 

 upon them. Something, however, may be done by com- 

 paring the reports of several shocks. Thus, if we take a few 

 dates, and arrange the ]3laces in the order of the time at 

 which the shocks are said to have occurred, we find : — 

 November 14, 1883.— Kent's Group, 2-45 p.m.; St. Mary's, 

 2-50 ; Swansea, 2-52 ; Launceston, 2-55 ; Gould's 

 Country,' 2-55; Falmouth, 3; George's Bay, 3 ; 

 Moorina, 3-5 ; Hobart, 3'10. 

 December 12. — Kent's Group, 6-45 p.m.; Gould's Country, 



6-48 ; Launceston, 6-59 ; Falmouth, 7 ; St. Mary's, 7. 

 March 28, 1884.— Goose Island, 11-28 p.m.; Launceston, 



11-36; Kent's Group, 11-40; Hobart, 11-45. 

 On May 10 and 1 1 the shocks were severe, and we find — 

 10.— Falmouth, 10-30 p.m.; Ross, 10-35; Kent's Group, 

 10-40 ; Launceston, 10-42 ; Hobart, 10-43 ; Goose 

 Island, 10-45 ; St. Mary's, 10-45. 

 11.— St. Mary's, 7*30 a.m.; Falmouth, 7-30; Kent's 

 Group, 7-35 ; Fingal, 7-35 ; Launceston, 7*36 ; Eoss, 

 7-37 ; Hobart, 7-40; Goose Island, 8 ; Circular Head, 8. 

 Then, June 17. — Kent's Group, 8-17 p.m.; Cape Barren 

 Island, 8-20 ; Goose Island, 8-25 ; Swan Island, 8-26 ; 

 Launceston, 8-26 ; St. Mary's, 8-30 ; Falmouth, 8-30 ; 

 Hobart, 8-30 ; Gabo Island, 8-55. 

 July 13. — Swan Island, 1-20 p.m.; Kent's Group, 1*35 ; 

 " Goose Island, 1-50 ; St. Mary's, 1-50 ; Falmouth, 

 1-55; Moorina, 1*55; George's Bay, 1*55; Upper 

 Eingarooma, 1*55 ; Launceston, 1*56 ; Hobart, 1-57 ; 

 Gould's Country, 2 p.m.; Wilson's Promontory, 1-43 ; 

 Eden, 2 p.m.; Gabo, 2-20. 

 August 29. — Swan Island, 10*55 a.m.; St. Mary's, 11 ; 

 Kent's Group, 11 ; Moorina, 11*5 ; Launceston, 11-5 ; 

 Hobart, 11-6 ; Gould's Country, 11*10 ; Falmouth, 

 11-15 ; Fingal, 11-15, 

 The severe shock on September 19 is reported as— Kent's 

 Group, 8-27 ; Fingal, 8-30 ; St. Mary's, 8-35 ; Gould's 

 Country, 8-35 ; George's Bay, 8-35 ; Launceston, 

 8-38; Swan Island, 8-39; Hobart, 8-40; Circular 

 Head, 8-40. 



