332 F. A. Perret — Report on the Messina Earthquake. 



only as a horizontal wave motion. It was followed by several 

 weaker movements. 



At 6.28 p. m. of Jan. 7, a shock lasting fully five seconds 

 formed the most interesting of those observed. The duration 

 was such as to give ample time to study the phenomenon and 

 it was impossible to avoid the conviction that the originating 

 movement at the centrum had a duration not greatly inferior 

 to that of the observed effect. This is contrary to the accepted 

 ideas of the day regarding earthquake generation and a dis- 

 cussion of the subject may be reserved for a future paper, but 



Fig. 11. 



Fig-. 11. Fronts fallen from houses, lying East and West. 



the writer feels in duty bound to record the impression in the 

 belief that no honest observation is without value. 



This shock was experienced when on board the U. S. S. 

 " Scorpion " and the man on watch reported having " seen " 

 the earthquake pass through the city from N. to S. When 

 interrogated he could give no more definite information, but 

 it is evident that the earth waves had produced a visible 

 undulation of the buildings and walls along the water front. 

 Many walls fell and the shock was followed by another not as 

 strong. A number of shocks occurred during the night and 

 in the early morning of the 8th. 



As to the cause of these Calabrian earthquakes, the writer 

 inclines to the opinion of Mercalli, viz.: that they are due to 

 the movements of deep-seated magma and belong, therefore, 



