2. With the face in the horizontal plane. 
3. With the face in the vertical plane, and facing either N.S., 
E.W., or 8.E., S.W., N.E., N.W. 
The gnomon always is parallel to the axis of the earth. 
For these latter observations on the construction of dials I am 
indebted to the kindness of Mr. Birch, who has sent me the 
observations of Mr. Romilly Allen, who conveyed them to him in: 
a letter on the subject of ring dials. In conclusion, he says, that 
the ring dial is only an apparatus for finding the altitude of the 
sun and thus obtaining the time. 
I may not inappropriately conclude this paper by quoting the 
motto from a sun dial erected at Torrington, Devon, and hope 
it may not be inapplicable to our present subject. 
"H SKIA KOY®H SO®IAN SE AIAASKETO. 
The Cause of Earthquakes. By Major WricuHt. 
(Read February 6th, 1884 ). 
The consideration of earthquakes and their causes, though 
happily not a subject of local interest (as would appear from some ~ 
remarks in an article in the January number of the Cornhill 
Magazine it ought to be), is however one that cannot fail to 
have engaged the attention of most of us from the frequency and 
terrible effect with which these convulsions of nature have lately 
visited so many parts of the world. But awful as these visitations _ 
have been, there is nothing novel in either their extent or their 
violence. Without going back to the recorded instances in ancient 
history, those of the last century alone furnish us with a list of ¥ 
destructive shocks greater probably than those lately experienced, 
