430 REPORT— 1886. 



possible value for h, as being equal. For sandstone I have assumed the 

 crumbling strength as being three-quarters of the breaking strength, 

 while for rubble work and brickwork it has been taken as one-half. (See 

 Rankine's ' Civil Engineering,' p. 361, &c.) 



The diameter of the base of each of these mountains is 48,000 

 feet, and the height to which mountains of the following different 

 materials could be built upon such a base without crushing would 

 approximately be : 



Brickwork 4,600 feet. 



Rubble masonry 7,300 „ 



Sandstone 14,500 „ 



Granite 20,000 „ 



10. Effect of Volcanic Eruptions on the People. 



From the translations of Japanese works relating to volcanoes which 

 I have given, it is seen that the eruptions of these mountains have from 

 time to time exerted a very marked influence upon the minds of the 

 Japanese people. Divine interference has been sought to prevent erup- 

 tions, priests have been ordered to pray, taxes have been repealed, 

 charities have been instituted, special prayers against volcanic disturb- 

 ances have been formulated and have remained in use for the period of 

 one hundred years, while special days for the annual offering up of these 

 prayers have been appointed. At the present day there is a form of 

 worship to mountain deities not uncommon, which may have had its 

 origin through the fear created by volcanic outbursts. Displays of 

 volcanic activity have certainly intensified this form of worship. 



Conclusion. 



In conclusion to this report, it gives me pleasure and satisfaction to 

 testify to the great work which has been accomplished, and the great 

 interest which is still being displayed in connection with seismological 

 investigation in this country. Professor Forrel, of Switzerland, speaking 

 at the Institution of Civil Engineers, testified to the gi'eat merit of the work 

 which has been accomplished in Japan, and remarked that the observers 

 of seismographs in that country had in two years accomplished more than 

 twenty centuries of European science had been able to show (' Minutes of 

 Proceedings of the Institution of Civil Engineers,' vol. Ixxxvi., session 

 1885-6, part 1, p. 40). Inasmuch as the grants of the British Association 

 have in no little measure assisted towards whatever may have been done 

 in Japan, it cannot fail to be of interest to the members of that Asso- 

 ciation to know the extent to which they have rendered assistance in 

 advancing seismological science in Japan. 



With the assistance of the British Association, an extensive series of 

 experiments lasting over several years were made upon artificially pro- 

 duced disturbances, which led to an insight into the nature and method 

 of propagation of earth-vibrations. It was with the assistance of the 

 British Association that a general seismic survey was made of North 

 Japan. One result of this work has been that the Imperial Government 

 of Japan has extended similar observations over the whole empire, and 

 now there are about 600 stations at which earthquakes are recorded. The 

 first complete seismograph made under the auspices of the British Asso- 

 ciation has been reproduced in this country, and is now being gradually 

 distributed throughout the empire. 



I 



