4:6 Dr. C. Davison on 



advance. It is applicable to shocks of every degree of 

 intensity ; and the tests are fairly definite, though they 

 depend too much on personal impressions. It is evident that 

 such may vary widely in different countries. In England, 

 for instance, the Hereford earthquake of 1896, which threw 

 down many chimneys near the epicentre, was the cause of 

 little, if any, actual alarm. In America, on the other hand, 

 the same degree of intensity during the Charleston earthquake 

 of 1886 caused many persons to camp out for the night. 



1. Very slight shock, noted only by seismographs or by a 

 seismologist. 



2. Weak shock, perceived by more than one. 



3. Slight shock, perceived by many persons, or announced 

 in the newspapers or by non-seismologists ; and of which the 

 duration and direction may be easily ascertained. 



4. Sensible shock, making fastenings, chandelier-prisms 

 (cristalli), and easily- moved articles shake ; creaking of floors. 



5. Moderate shock, perceived generally by very many 

 persons, making a few bells in towns ring ; felt by non- 

 seismologists in many places not very near one another ; 

 causing beds to shake. 



6. Rather strong shock *, with more or less ringing of bells, 

 oscillation of lamps, stopping of clocks, in towns ; and, in the 

 country, visible or sensible quivering of trees and shrubs ; 

 some persons say that fortunately no damage occurred ; 

 through fear or prudence some go out into the open air ; 

 almost general interruption of sleep at night. 



7. Strong shock, with fall of plaster, ringing of church 

 bells, noise and general alarm without damage, fall of objects 

 and pictures. 



8. Very strong shock, with fall of chimney-pots, cracks in 

 buildings, flight of persons from houses. 



9. Ruinous shock, with total or partial fall of some 

 buildings. 



10. Disastrous shocks, with great destruction and loss of 

 life. 



(5) Forel Scale. — Arch, des Sci. phys. et nat. (Geneva), 

 vol. vi. 1881, pp. 465-466. 



Without knowing of the existence of the Rossi scale, a 

 somewhat similar scale was devised by Prof. F. A. Forel, a 

 prominent member of the Swiss Seismological Commission 



* The original adjectives in degrees 6, 7, and 8 are "forte," "molto 

 forte " and *' fortissima " ; for which we have not exactly similar ex- 

 pressions. In the Forel and Mercalli scales, the same or similar terms 

 occur and are translated in the same way. 



