vm, a, 4 Saderra Maso and Smith: Seismic Disturbances 205 



but merely a coordinated collection of data which might serve as a 

 basis for the future study of the earthquakes of the Philippine 

 Archipelago. Many of these data were in the archives of the 

 Manila Observatory and had not been published previously, 

 while others were to be found scattered in histories, periodicals, 

 and other publications. 



The only important conclusion he draws is that the seismic 

 center dangerous for Manila does not lie in the existing volcanoes 

 south and southeast of the city, but in the eastern range of 

 mountains and especially in the part east-northeast and northeast 

 of Manila. 



The same writer 9 has given accounts of the more important 

 earthquakes that have taken place in the different parts of the 

 Archipelago. During the first period he endeavored as a rule 

 to trace a relation between earthquakes and volcanoes. In the 

 second period — that is, 1900 to 1912 — he inclined to the more 

 modern ideas in certain of his papers, 10 although he exaggerates 

 the importance of volcanic manifestations when he speaks of the 

 different epicenters of regions of greater seismic activity. 



Since 1907 this investigator has written several short papers " 

 on the seismicity of the different regions of the Archipelago as 

 a preparation to a more complete work like the present. In 

 these articles he has attempted to indicate by the alignment of the 

 different epicenters the possible existence of seismotectonic lines, 

 in conformity with the recent principles of seismology. 



In 1899, Koto 12 published a valuable study in which he 

 discusses the different tectonic lines and volcanic belts of the 

 Philippines and their connection with Celebes, Borneo, and the 

 Moluccas. It is a thorough and complete study of great value, 



* Monthly Bulletins of the Manila Observatory, 1890 to 1897, and from 

 1900 to 1912. 



10 Report on the seismic and volcanic centers of the Philippine Archi- 

 pelago. Manila (1904); Volcanoes and seismic centers of the Philippine 

 Archipelago. Washington (1904), as part of the census of the Philippine 

 Islands. 



"The earthquakes of Ambos Camarines, Bull. P. I. Weather Bur. (1907), 

 172; The earthquakes of the Batanes Islands and southern Formosa, ibid. 

 (1909), 97; The seismic centers of northern Luzon, ibid. (1909), 131; 

 Submarine seismic centers near the coasts of northern Luzon, ibid. (1909), 

 167; Seismic centers near western Mindanao and Jolo, ibid. (1909), 203; 

 Seismotectonic lines in southern Luzon, ibid. (1911), 409. 



u On the geological structure of the Malayan Archipelago, Journ. Coll. 

 Sex., Imp. Univ. Tokyo (1893), 5, pt. II, 2. 



