265 



obtained iu particular places, or under special circsmstances. 

 such as tlie effect produced on tlie waters of tlie sea, or of 

 lakes, and if any alteration is observed in the flow of rivers 

 and streams, bow far the shock was felt in mines, and in 

 what way, etc. 



Now, let us see what can be gathered from the observations 

 which have already been made in Tasmania. 



Unfortunately, as already mentioned, the shocks have been 

 too slight for us to hope for any information on many of the 

 points enumerated, while the report? do not agree sufficiently 

 as a rule to enable us to speak with much confidence on 

 others. 



The first thing that strikes one on looking over the 

 tabulated reports is the enormous number of shocks which 

 have been felt. Thus, in the month of February, 1884, 

 nearly one hundred shocks and tremors were felt at St. 

 Mary's, and in some months of 1883 and 1884 this number 

 has been exceeded. Similarly numerous are the reports from 

 Gould's Country and Moorina, so that since April 12, 1883, 

 when the first shock was recorded at Gould's Country, over 

 one thousand distinct shocks have been felt, besides many 

 which must have passed unnoticed. Of course a very large 

 number of these were mere tremors, and such as would be 

 likely to pass unnoticed by most people. Indeed, one doubts 

 whether they would be felt at all were not their attention 

 attracted by the noise which so often appears to iwecede the 

 shock. 



Any one who has lived in the vicinity of a railway, 

 especially one on which heavy luggage-trains pass at a high 

 rate of speed, will know what very slight tremors may be felt 

 at a comparatively long distance from the source of vibration. 

 Although every shock reported is carefully tabulated at the 

 Meteorological Office, with the date^ alleged time, whether 

 severe, slight, etc., it will only be desirable to allude indi- 

 vidually to a few of those which, from their severity and the 

 wide area over which they were felt, are of special importance 

 and interest. 



The great .majority of the slight shocks do not seem to 

 have been felt beyond the N.E. parts of Tasmania, so that 

 the centre from which they originated would seem to be not 

 very far off, although probably under the sea. As to the 

 severer shocks, I have prepared a table showing the places 

 where some of them were felt, and the reported time of occur- 

 rence. Before discussing the table it may be well to state 

 briefly what is to be learned from it. 



It is, of course, known that the shocks are supposed to 

 originate at about the same place ; and if we find that the 

 same shock is felt at certain places at the same time, we 



