VULCANOLOGY AND SEISMOLOGY. 470 



and Segovia, toward the west by C^ceres and Huelva, toward the east 

 by Valencia and Muniia, and on the south by the Mediterranean; but 

 the tremor of the earth was also indicated by instruments even so iar 

 distant as Rome and Brussels and Wilhelmshaven. {Nature^ XXXI: 491.) 

 Examination of the direction of the cracks in the ground and in build- 

 ings, as well as of the curves of intensity estimated ac(;ording to the 

 Eossi-Forel scale, leads to the conclusion that the focus is to be found 

 in the valley of Zaffaraya, where the greatest damage was caused. The 

 latter half of the report is occupied with the physical, magnetic, barom- 

 etric, and other ph'^nomena attending the earthquake. The number of 

 buildings injured in the two i)rovinces is stated at 17,178, of which,4,39U 

 are classed as totally destroyed. The injured persons numbered 745 

 dead, and 1,485 wounded. In discussing the cause of this earthquake 

 the commission accepts the Italian theories, attributing earthquakes to 

 the tension of the vapor of water in the subjacent strata. The valley 

 of Zaffaraya. indicated above as the probable focus, is a locality where 

 much water gathers and easily penetrates beneath the surface, and to 

 the vapor of high tension produced from the water here collected in 

 deep lying strata are attributed the forces which gave rise to the ])resent 

 earthquake. The commission consisted of M. T. de Castro, J. P. Lasala, 

 Daniel de Cortazar, and J. Gonzalo y Tarin. 



On March 2, M. Fouque gave to the French Academy a preliminary 

 report on the exploration which the committee under his charge had 

 made of the phenomena of the Spanish earthquakes. The committee 

 consisted of MM. Fouque, L6vy, Bertrand, Barrois, Offret, Kilian, 

 and Bergeron, and was accom])anied by M. Breon. This first commu- 

 nication speaks only of their journey, the facilities atibrded by the Span- 

 ish authorities, and certain phenomena observed, reserving the discus- 

 sion of theoretical questions to another time. {Compt. Rend., c: 598.) 



The full reports of the French committee may be found in (Jomptes 

 Rendus Tome c, and besides a general consideration of the ])henomena 

 and their cause, they include two special reports on the geology of the 

 distri(;t by members detailed for that ])uri)Ose. In the general con- 

 clusions reached they agree with tlie Spanish commission, and fix the 

 <3entrum in an elliptical area surrounding Zaffaraya; but in regard to 

 the cause of the disturbaiuie M. Fouque rejects the theory whicli at- 

 tributes it to the lo(;al tension of water va})or, and would refer it rather 

 to the genenil volcanic forces within the globe. 



The Meteor olocjUehe Zeitschrift for February, 1885, contained a notice 

 by ])r. Esclienhageu on the etiect which was apparently inodnced by 

 the Andalusian earthquakes on the magnetic apparatus at VVilhelms- 

 havcn. The effect seems to have been not at all of a magnetic chara'j- 

 ler, but i)urely mechanical, the delicately suspended magnets acting as 

 the pendulum of a seismoscope. Attemjits to draw from the observed 

 times some inference as to the rate of propagation of the disrnil>ance 



