474. C. G. Rockwood, Jr.—Japanese Seismology. 
ner’s re iia pendulum, due originally to Chaplin and im- 
prov y Ewing and Gray. It consists essentially of a 
Geis supported on a horizontal bar, which is attached at 
one end to a vertical axis and at the other end carries a lon 
pointer writing upon a moving plate. is will of course 
record only one component of the motion, viz: that at right 
angles to the direction of the pointer, and such apparatus must 
be used in pairs placed at right angles to each other 
The apparatus for vertical motion, which was used in connec- 
tion with this, was a vessel of water supported from above 
and having a flexible bottom, which would be acted upon by 
the inertia of the liquid and would make its record by a multi- 
plying lever upon a moving plate. 
A modification of the conical pendulum by Gray * promises 
to afford a very sensitive ene but it cannot well be de- 
scribed without diagram 
Milne’s tremor sadieisiee + are also most delicate and sensi- 
tive. From a rigid frame is suspended, by a short wire, a 
the heavy mass relative to its sup ort causes motion of the 
rs, an of a beam of light reflected from the mirrors. A 
motion of an inch is readily detected in this wa 
the Seismological Society of Japan and in the ot ther papers 
above referred to, and to these 9 the reader is referred 
for “ipa information in regard to t 
e now to consider some ee obtained by the use of 
eienoante and the discussion of their records. The published 
volume of Transactions of the Seismological Society, Part II, 
contains from the pen of John Milne, a ‘jong account, amount. 
ing to over one hundred pages, of the earthquake of February 
22, 1880. It is based on one hundred and twenty written com- 
detailed replies to a series of printed questions. Our limits 
forbid anything more than a brief statement of a few selected 
ints 
Pothe direction of the shock was eet from personal 
reports and from the indications of Palmieri’s instrument, a 
Cacciatore and a pendulum recording its janie on a smoked 
glass. The general result was that there had been two shocks, 
the first in a direction approximately to or from N.N.W., the 
* sone siete: Mag., Lc 
“On Recent Harthquake Investigations,” by T. Gray in Chrysanthe- 
mum, ot 1, No. 5, May, 188 
