42 



EEPORT — 1901. 



40 per cent, at one or more stations in Europe.^ These latter refer to 

 Strassburg, Hamburg, Laibach, Trieste, or observatories in Italy. 



From what has been said it is clear that results indicated by the 

 above table are, when we have at our disposal materials more definite in 

 character, open to modification. 



Numerous records, as at Shide (210) and Kew (220), may indicate 

 that in the examination of the record-receiving films, in certain instances, 

 minute disturbances have been wrongly accepted as having a seismic origin. 

 The high number of records accredited to Batavia may partly be accounted 

 for by the fact that at that place there are many local shocks the effects 

 of which have not been appreciable at distant stations. That the per- 

 centage of the Shide records noted at other stations is, in all instances but 

 one, greater than the percentage of the Kew recoi*ds at corresponding 

 stations (see the first two horizontal lines in the table) indicates that 

 either the Kew instrument or the ground on which it rests is less sensi- 

 tive to seismic influences than the instrument or the ground at Shide. 

 A similar conclusion is arrived at if we inspect the two vertical sets of 

 entries beneath the names of these two stations. 



The fewness of the San Fernando and Bombay records, and the large 

 percentage of these which are found at other stations, may indicate that 

 at these stations disturbing influences non-recognisable as seismic but 

 rarely occur. For Cairo and Calcutta not only are the records few in 

 number, but the percentages of these common to other stations are also 

 low. The explanation of this probably rests on the fact that these two 

 stations are installed upon alluvium. At San Fernando and Bombay, 

 where the installations are upon hard materials, although the records are 

 not numerous, the percentages of these recognised at other stations are 

 high. If this is correct we have here the reverse of what occurs in the 

 case of earthquake motion that can be felt, the motion being greatest 

 upon the alluvium, and least upon the harder strata. 



The low percentages corresponding to the Cordova records may be 

 accounted for by the supposition that many of its entries refer to shocks 



' See footnote to p, 47. 



