354 < -Mr. Christie o« the diurnal deviations of the 
lflth April. Morning cold and cloudy ; wind N. W. strong. 
Time. 
Direction of 
Needle. 
h. m. 
0 / 
o 40 
8 16 W 
0 50 
9 24 W 
Showers of hail and heavy rain. 
1 15 
7 08 W 
f A heavy cloud and hail shower in W : cloud apparently highly 
l electric. 
I 50 
7 00 W 
Cloud passed to S ; sun bright. 
2 00 
5 40 to 
5 50 W 
| At several observations. 
4 45 
1 00 W 
f Gradually decreased to o° 10' W. A heavy shower of hail : the 
\ cloud from W, though S to E and in zenith. 
6 15 
0 18 E 
7 00 
0 56 W 
\ A heavy cloud from N to NW ; greatest height that of the 
7 05 
0 16 W 
/ equator of the dipping needle. 
7 25 
7 32 
0 10 W 
Cloud passed to S. 
f Changed to o° 50' W, i° 40' W, 2 0 oo'W, then gradually went 
\ back to i° io' W, o° 50' W, o° 40' W, settling at o° 30' W. 
7 43 
0 30 W 
In some of my first observations, I had noticed that the 
directions of the needle were different, according as I stood 
to the east or to the west of the needle ; and although I did 
not then attribute this effect to the right cause, namely, a 
very minute change in the level of the instrument, I always 
took particular care, by placing myself directly in front of 
the instrument when I observed, that this should not affect 
the observations : in those which I am about to describe, the 
possibility of any effect of this kind was avoided by the in- 
strument standing on a stone floor, which was laid on the 
ground itself. 
Having ascertained the general character of the deviations 
when the north end of the needle pointed towards the north, 
my next observations were with a view of comparing with it, 
that of the deviations when the north end pointed towards 
the south. For this purpose the magnets were brought 
