VTTLCANOLOGY AND SEISMOLOGY. 48^) 



J. Le Conte suggests that a reason for it may be found in a principle 

 of wave motion published by Airy in 1849. A normal sea "w^ave strik- 

 ing against a wall will be reflected, but if a "broken headed" wave or 

 breaker strike such a wall the normal part only will be reflected, while 

 the broken part, if it strikes perpendicularly, will be destroyed, or if it 

 strike at a small angle, will then run along as a strong wave clinging 

 to the surface of the wall. He regards the surface of the earth as a 

 reflector for earthquake waves, and notes that the waves themselves 

 are pre-eminently broken waves, and hence ought to follow the above 

 law. {Science, Yi: 540.) 



A fourteen-page note on the East Anglian earthquake of April 22, 

 1884, with two maps, occupied nearly the whole of Symou's Meteorologi- 

 cal Magazine for ]May, 1884. A full report on the same earthquake by 

 R. Meldola and William White, illustrated by numerous photographs, 

 was read before the Essex Field Club in March 1885 {Nature, xxxi : 

 395). It forms a book of 225 pages and deals very fully with the cir- 

 cumstances of the earthquake. It is divided into eight sections, of 

 which the first is historical, giving a catalogue of sixty previous British 

 earthquakes from A. D. 103 to 1881 ; the second describes the method 

 of securing information, and the third and fourth are devoted to the 

 phenomena of the shock. In summarizing this portion it is stated that 

 "the main axis of disturbance extends on each side of a line about five 

 miles in length, having a direction northeast and southwest from 

 W^ivenhoe to Pelton." In other portions of the report the geological 

 relations are considered, the effect of the shock on the underground 

 waters, and the correspondence in direction of the seismic hx\s with fault- 

 lines and with the coast-line of Essex. In speculating on the cause of 

 the earthquake the authors only venture to suggest "a sudden rupture 

 of deep-seated rocks under a state of strain"; and add — " the precise for- 

 mation in which this rupture occurred cannot even be conjectured." 

 {Nature, xxxiii: 265.) 



Dr. H. J. Johnston-Lavis announced the approaching publication, by 

 subscription, of a " Monograph of the Earthquakes of Ischia," a memoir 

 dealing with the seismic disturbances in that island within historic 

 times, with special observations on those of 1881 and 1884. {Nature, 

 XXXI : 563.) 



Before the Seismological Society of Japan, Professor Koto read a 

 paper on " Movements of the Earth's Crust," observed in Japan, con- 

 cluding that the south and east coasts are gradually rising, while the 

 north and west coasts are subsiding. This phenomenon is no doubt 

 connected with the greater seismic activity along the eastern sea- 

 board, shown by the fact that almost all of the earthquakes felt at 

 Tokio come from the east and southeast. At the same meeting, K. 

 Sekiya, who is in charge of the Seismological Observatory of the Uni- 

 versity of Tokio, described in detail the earthquake of October 15, 1884, 

 which afiected an area of 24,728 square miles, and noted its similarity 

 to that of February 22, 1880, both originating on the east side of the 



