horizontal needle when under the influence of magnets. 359 
agree most nearly with one-another at the same point : they 
are. 
At South. At North. 
2 52 
3 4 — 
3 8 3 2 4 
32 3 28 
3 16 3 26 
3 16 3 26 
Means 3 6 3 26 
and the proportion of the intensities 100 s to 105% would give 
3 0 6' and 3 0 25'. 
Being desirous of observing the changes from the earliest 
time in the morning, I commenced the observations on the 
26th, at 2 h 15 111 A. M. and continued them throughout the day 
at intervals of half an hour, and sometimes less, until n h 
P. M. As they exhibit very minutely all these changes, and 
point out clearly the early period at which they commence, I 
here subjoin them at length. In the second columns are the 
directions which the needle had when undisturbed at the 
times specified in the first columns, and in the third are the 
points at which it settled, at the times marked in the fourth 
columns, after being very gently vibrated. Where there are 
two directions corresponding to any time, it indicates that, 
when observed, the needle kept vibrating between them. I 
have added the morning observations of the 27th till past 
the easterly maximum, that the evening deviations might 
again be connected with those of the following morning in 
one view. At 1 i h 15“ P. M. April 25th, the needle pointed 
-f- 2 00. 
