ON SEISMOLOGICAL INVESTIGATION. 



149 



one list. The following list only includes movements which have an 

 earthquake-like character ; but as it is possible that certain small displace- 

 ments may have been mistaken for earthquakes when examining the list, 

 the following explanatory notes will make it easy to identify records which 

 are doubtful. 



The sign > , or a series of such signs, indicates a small movement, or 

 a series of small movements, with an amplitude of about 1 mm., which 

 commenced suddenly and ended gradually. It is quite possible that some 

 of them, at least, may be due to some local cause — as, for example, a slight 

 settlement beneath the pier on which the instrument is rested — and there- 

 fore are not earthquakes. The sign --^, or a series of such signs, indicates 

 a very small movement, or series of movements, which commenced 

 gradically and ended gradually. Such movements have a true earthquake 

 character ; but because I have no record where they were nearly simul- 

 taneously recorded at Carisbrooke, they must, in many instances, at least, 



be of local origin. 



Disturbances which are ' moderate,' or disturbances which have 

 amplitudes exceeding 2 mm., if these commence gently it may be as- 

 sumed that they are of earthquake origin. 



All large disturbances commencing with decided preliminary tremors 

 are certainly earthquake effects. Those to which an asterisk is attached 

 are described at the end of the list in more or less detail. The materials 

 for their description have been derived from my own observations, obser- 

 vations made in Japan, communications from various observers in Europe 

 and Great Britain, the ' Bolletino della Societa Sismologica Italiana,' thte 

 columns of ' Nature,' and other sources. 



Earthquakes observed at Shide, Isle of Wight, 1896-97. (_All times are given in 

 Greenwich mean astronomical time. Midday or noon = or 24 hours^ 



No. 



Date 



Hour of com- 

 mencement, 

 G.M.T. 



Remarks 



1896. 



H. 



22 



10 



9 



13 



13 



14 



9 



9 



9 



10 



18 



9 



10 



11 



12 



8 



M. S. 



30 



6 26 

 47 56 



8 35 

 58 59 

 30 19 

 27 17 



2 26' 

 24 45, 



6 



57 

 1 

 51 

 13 

 53 

 22 



Large ^ > 

 Small > 



Four maxima 

 Small -^ 



