489 



effects observed, the description generally of the places examined 

 and phenomena observed, embracing many examples of fissures in 

 earth or rock, falls of rock, landslips, changes of water-courses, &c., 

 and the explanation of their conditions, the observations con- 

 tinually made to correct the magnetic decimation for the observa- 

 tions of wave-path by compass, the hypsometric determinations by 

 the barometer of many points of elevation, geological sections 

 over certain parts of the country examined, the time observations 

 obtained for determination of transit velocity. The descriptions are 

 illustrated by numerous sketches made by the author on the spot, by 

 diagrams and topical maps, and by a large series of photographs, made 

 under the author's instructions, by a photographer who followed in 

 his track. 



In the appendices to this part the author has given translations 

 of all the notices that appeared in the ' Giornale Reale ' (the only 

 Neapolitan newspaper), of the events of the shock, with tables of 

 the meteorology of Naples, from those of the Royal Marine Obser- 

 vatory, for certain periods before, during and after the shock ; also 

 returns of the population, area, damage, deaths and number of 

 wounded persons in the shaken provinces. 



In the third and concluding part the author colligates all his facts, 

 classifies them, and draws his conclusions and generalizations under 

 the following heads : 



a. The superficial position of the seismic vertical. This, the 

 author shows from the independent and concurrent evidence of above 

 70 separate wave-paths, was close to the village of Caggiano, near 

 the E. extremity of the valley of the Salaris ; the evidence being 

 of a highly cumulative character, as the intersection of two wave- 

 paths only is sufficient to determine this point. 



b. The depth of the focal point below the sea-level. This, the 

 author shows, was about 5| geographical miles, . e. the mean focal 

 depth. 



c. The forms and areas of the meizoseismal and the several 

 isoseismal curves. These have been laid down by the author upon 

 three large maps, protracted from Zannoni's great map of the 

 kingdom of the Two Sicilies, upon a scale of more than half an inch 

 to the geographical mile. 



Of these, the map A shows the wave-paths as determined in 



