Scales of Seismic Intensity. 49 



4. Strong, with more or less general ringing of bells, stop- 

 ping of clocks, oscillation of lamps. 



5. Very strong, with fall of plaster and of a few chimney- 

 pots, cracks in buildings, ringing of bells. 



6. Almost ruinous, with total or partial fall of a few (one 

 or two) buildings. 



7. Ruinous ; ruin of several buildings, a little loss of life. 



(9) Japanese Scale. — Report on Earthquake Observations 



in Japan (1892), p. 10. 

 With the exception of the Comrie scale, that employed in 

 Japan is less useful than any other mentioned in this paper, 

 on account of the small number of degrees which it contains. 

 At first sight, it is surprising that this should be the case in 

 the country which possesses the most complete organization 

 for the study of earthquakes. One reason may be the reliance 

 placed on seismographs, but I think that the chief reason lies 

 in the great frequency of earthquakes in many parts of Japan. 

 With the exception of those which are unusually strong for 

 the districts concerned, records are obtainable as a rule only 

 from previously prepared observers. The detailed inquiries 

 which are possible in Great Britain can hardly be made in a 

 country in which the recollection of one shock is soon after 

 dimmed or erased by the occurrence of another or many more 

 in rapid succession. 



1. Slight, just sufficient to be felt. 



2. Weak, when the motion is distinctly felt, but not so 

 violent as to be necessary for people to run out-of-doors. 



3. Strong, when most people run out-of-doors, some pieces 

 of furniture are overturned, liquids thrown out, buildings 

 damaged, the ground cracked or rent. 



(10) Mercalli Scale.— -Prof. G. Mercalli, ' I Terremoti della 



Liguria e del Piemonte/ p. 20 (Naples, 1897). 



The Mercalli scale is a modification of the Rossi-Forel scale, 

 and is now adopted as the standard of the Central Office of 

 Meteorology and Geodynamics at Rome. The degrees do not 

 correspond exactly with those of the Rossi-Forel scale, and 

 the equivalents given in the Table below are only approxi- 

 mate. The limitation of both scales to ten degrees renders 

 the Mercalli scale rather more suitable for disastrous earth- 

 quakes, and the Rossi-Forel scale for shocks of moderate 

 intensity. 



1. Instrumental shock, that is, noted by seismic instru- 

 ments only. 



Phil Mag. S. 5, Vol. 50. No, 302. July 1900, E 



