1897 - 98 .] Note on Indian Earthquake, 12 th June 1897 . 13 
magnetical disturbances — in this instance more, perhaps, by the 
latter than by the former, which was feeble, as stated above. The 
trace shows some evidence of being affected by two causes super- 
imposed upon each other, specially at the end of the disturbance, 
where the blurred trace, probably due to change in the focal 
distance caused by a slight displacement of the mirror, appears 
suddenly to pass from a faint to a somewhat deep impression, 
bounded by convex curves. 
Movement in the vertical force magnetograph now remains to be 
inquired into. This instrument is under an exhausted receiver, 
but its knife-edge is somewhat faulty, and this magnetograph is 
therefore peculiarly sensitive to shocks — an accidental fall of a 
lamp-chimney, heavy tread of visitors, and even a slight knock of 
the hand, results in dislocation of the curve. And such disloca- 
tions being frequent, special care is always taken to guard the 
instrument from such accidents. 
And yet no dislocation of the curve is noticed during the earth- 
quake, which more or less establishes the fact that the movement 
of the earth must have been very feeble. But the instrument does 
show vibrations, which naturally leads to the inference that they must 
have been caused by some magnetic action, the first vibration of 
which is timed to have taken place exactly when the declination 
trace is just lost by the second wave. And it would thus appear 
as if the seismic convulsion was in some way the cause of the 
magnetic action, the latter phenomenon running parallel to the 
former, increasing as it increased, and subsiding as it subsided, 
every seismic wave having its companion effect in a magnetic 
wave. 
With regard to the direction, since the barograph would not 
show any indication of direction, nor the magnetographs, all of 
which appear to have been disturbed by the magnetic action, it is 
difficult to come to any definite conclusion. Except, perhaps, in 
the case of declination, the suggestive explanation given later on, 
if true, would point, at least, that the direction was inclined more 
to c east to west’ than to ‘north to south.’ And from the 
mechanical disturbance of the magnets of the two instruments, 
declination and horizontal force, which are suspended at right 
angles to each other, the more pronounced motion observed during 
