C. Davison — British Earthquakes. b7 



5 mm. in length), from the Permian beds of Tscherdyn on the 

 Kolwa, on the western side of the Ural. 



EXPLANATION OF PLATE II. 



Fig. 1. Est heria Andreivsii, s^. noY. Left valve of the short form ; magn. 4 diam. 

 ,, 2. ,, ,, Eight valve of the long form ; magn. 4 diam. 



,, 3. ,, ,, Portion of surface; magn. 50 diam. 



„ 4. ,, ,, Another part of the surface, showing the inside of one 



layer, the impression of its outside on the matrix 



(dark) ; magn. 50 diam. 

 ,, 5. Estheria Sindei, sp. nov. Left valve ; magn. 6 diam. 

 „ 6. ,, ,, Portion of the beaded concentric striae ; magn. 50 diam. 



,, 7. ,, ,, Portion of an interspace ; magn. 50 diam. 



„ 8. ,, ,, Portion of two interspaces ; magn. 50 diam. 



,, 9. Estheriella costata, "Weiss. Right valve; magn. 10 diam. 

 „ 10. ,, ,, a, Part of the inside of a right valve ; magn. 10 diam. 



b, Portion of the same ; magn. 50 diam. 

 ,, 11. Estheriella nodocostaf a (GieheV). Left valve ; magn. 10 diam. 

 „ 12. Est/wria miiiufa {Alherti). Possibly i?. G^^rw^ri (Beyrich) ; magn. 10 diam. 

 ,, 13. Estheriella nodocostata (Giebel). a, Inside of left valve ; magn. 10 diam. 



6, Portion of the same ; magn. 50 diam. 

 ,, 14. Estheria minuta, var. Brodieatia, Jones. Left valve ; magn. 5 diam. 



11. — On the British Earthquakes of 1889.^ 



By Chakles Davison, M.A., 



Mathematical Master at King Edward's High School, Birmingham. 



TPEOPOSE in this paper to write a short account of the earth- 

 quakes that have been felt in Great Britain during the year 

 1889, and to consider the relations of these earthquakes with the 

 geological structure of the districts in which they occurred. The 

 attempt seems to me worth making, for two reasons. The first is 

 that, though few in number and slight in intensity, the earthquakes 

 which visit this country are individually and in their connexion 

 with preceding shocks, of considerable interest. And, secondly, the 

 accounts, even when published, are widely dispersed, and, appearing 

 chiefly in local newspapers, become difficult of access in after years. 

 I believe, therefore, that an attempt to collect and discuss these 

 scattered observations cannot be without some value. 



I will, in the first place, describe the nature of the evidence on 

 which these accounts are founded. For the two more important 

 earthquakes, the chief authorities are the newspapers published 

 within and near the disturbed areas. In a few cases, the notices 

 they contain are far from satisfactorj'^, and bear obvious signs of 

 exaggeration,'^ But, in certain respects, their evidence seems to be 

 trustworthy ; and, as a general rule, I believe we may rely on them 

 for a knowledge of the places where a shock was or was not felt, of 

 the places where it was accompanied by the characteristic earthquake 

 sounds, and also for a record of the effects of the shock sufficient to 

 enable us to determine its intensity according to the Kossi-Forel 

 scale. 



1 A paper read before the Royal Society, June 19, 1890, and published in abstract 

 in the Koy. Sec. Proc. vol. 48, pp. 275-277. 



^ For example, the statement that, during the Edinburgh earthquake of Jan. 18, 

 a boy -was thrown out of bed at Gogar, is evidently inaccurate. 



