36 bulletin: musel'm of comparative zoology. 



damage was most severe along the water-front where the alluvial 

 deposit and made-ground imposed the thickest layer of loose uncon- 

 solidated material upon the bed rock. In this zone many buildings 

 were completely levelled. Nearer the base of the cliff which partly 

 separates the upper from the lower portion of the city, buildings stood 

 with their walls cracked and cornices broken away but frequently 

 otherwise safe for habitation. Upon the sloping ground above the line 

 of cliffs where a superficial layer of weathered rock on the inclined 

 surface had slipped down carrying buildings with it, and in the ceme- 

 tery where similar conditions existed, the destruction was most pro- 

 nounced. The reconstruction of the business houses along the 

 incoherent ground of the water-front insures a recurrence of the tale 

 of destruction when in the future the seismic movement affects in this 

 vicinity the line of displacement which skirts the coast of Chile. 

 From the studies of Dr. H. Steffen in the case of this earthquake the 

 disturbance appears to have had its origin off Coquimbo, a sea-port 

 198 marine miles north of Valparaiso. 



I was impressed with the fact that in a large number of the houses 

 that were not completely destroyed the damage was at a maximum in 

 the peripheral parts of the buildings; that though one or more of the 

 outer walls were demolished or thrown outward, the internal walls 

 and the inner angles of the floors were left standing in place unen- 

 cumbered by fallen wreckage in such a manner that persons unable 

 to leave these buildings would have escaped with their li\es had they 

 sought refuge during the height of the shocks in the internal corners 

 of the rooms. I had occasion later to note instances of the same sort 

 amid the ruins of Kingston, Jamaica, produced by the earthquake 

 of January 14, 1907. It would seem advisable from this observation 

 that houses in earthc^uake countries should be constructed with one or 

 more sets of rectangularly intersecting, internal walls well united of 

 materials whose period and amplitude of vibration as a mass is 

 identical so that one end of the building will vibrate as nearly as 

 possible in unison with the other. From the lack of this synchroneity 

 and equality of lateral swaying the outer walls will probably be thrown 

 off or toppled down but the central structure of buildings properly 

 balanced, as numerous examples have shown, often stands and by a 

 slight special construction adapted to the purpose, the internal angles 

 of such intersecting walls might in many cases prove places of refuge . 

 and security. 



This Chilean earthquake, coming at a time when the people of the 

 United States were preoccupied with the calamities of the similar 



