DYNAMICAL GEOLOGY. 28 1 



standpoint, and placed great importance on evidences 

 of the interchangeable relations subsisting between earth- 

 quakes and volcanoes. Naumann contended, in opposition 

 to Humboldt's generalisation, that certain earthquakes might 

 be termed plutonic, in so far as they occurred independently 

 of volcanic influences; Von Seebach also attributed earth- 

 quakes in some instances to local disturbances of crust- 

 equilibrium, not necessarily associated with the earth's 

 volcanicity. Since Humboldt's famous description of the 

 Cumana earthquake, great advances have been made in the 

 knowledge of the geographical distribution of earthquakes, 

 the methods of determining the position of seismic foci, and 

 the rate, the intensity, and the mode of propagation. 



One of the most indefatigable bibliographers of earthquake 

 phenomena was Professor Alexis Perrey in Dijon. Between 

 the years 1841 and 1874 Perrey collected statistics of 

 earthquakes extending back for more than fifteen centuries. 

 In England, Robert Mallet and his son J. W. Mallet 

 published an Earthquake Catalogue for the period i6o5- 

 1858; Muschketow collected the data of the Russian and 

 Central Asiatic earthquakes ; in Germany, Hoff and Berg- 

 haus published in 1841 a catalogue of volcanic eruptions 

 and earthquakes, and C. W. Fuchs kept a regular chronicle 

 of observations from 1873 to 1885; Volger published a 

 careful account of the Swiss earthquakes, together with some 

 notes on the periodicity, propagation, and extension of the 

 shocks. 



Italy, so frequently the scene of destructive earthquakes, 

 possesses in De Rossi, the founder of " underground 

 meteorology," a historian of equal rank with Perrey. De Rossi's 

 chief work, published 1879-82, comprises his own valuable 

 observations and regular records kept for several decades in the 

 seismological observatory which he erected at Rocca di Papa 

 in the Alban mountains. 



Baratta carefully compiled all the records of the terrible 

 earthquake in the year 1627, which devastated the peninsular 

 area of Monte Gargano. The Neapolitan earthquake of 

 1857 was recorded in a masterly and suggestive paper by 

 Mallet. The violent shocks during the last decades of the 

 nineteenth century at Belluno (1873), Ischia (1883), and 

 Liguria (1887), have been made the subject of a large number 

 of publications by foreign geologists and meteorologists. A 



