The Disturbance of Isomagnetics 

 attending the 



Mino-Owari Earthquake of 1891, 



By 

 A. Tanakadate, Riéàkuhakushi, F. R. S. E, 



Professor of Physics 

 and 



H. Nagaoka, Rié^kushi, 



Assist. Professor of Physics. 

 College of Science, Imperial University. 



Plate XV-XXII. 



Introduction, 



One of the severest earthquakes in the record of this country 

 devastated the districts alwut Gifu and Nagoya, on the 28th October 

 1891, of whicli a full account will shortly appear in this Journal. 

 The Science College of the Imperial University, at tlie request of the 

 writers, appointed a survey party, consisting of the writers and two 

 advanced students of physics, Messrs. Ota and Nakamura, for a new 

 magnetic survey of the district affected. Frequent shocks of varying 

 intensity occurred for a very long period after the date of the 

 destructive one in October, and the party did not set out till some 

 time after these shocks had sensibly ceased, namely, on the 20th 

 December, returning on the 13th January. 



The object in view in having this survey made, was to enable 

 comparisons to be drawn between its results and those which had 



