horizontal needle when under the influence of magnets. 379 
From these we see, as before, that the westerly and easterly 
points approach and recede from the north together, with a few 
exceptions, which happen about eight o’clock in the morning 
and three o’clock in the afternoon. The nearest approach of 
these points towards the north, or their greatest deviations in 
the directions minus and plus, appeared to take place about 
noon. The changes in the southerly point again agree very 
nearly with the observations at the south from the 20th to 
the 27th of April : the maximum in the direction minus ap- 
pearing to happen about an hour after noon. 
The following observations were made with the compass 
No. /, having the magnets adjusted on the same horizontal 
table, in the open air, as I have described previous to the 
observations with it on the 1 ith of May. During the same 
time that these were made, I likewise made those with the 
compass No. II . : the two sets were made in the following 
order ; those with No. II. were begun a few minutes before 
the hour, so as to finish those with No. I. at nearly the same 
time after it, the whole time occupied being, in general, about 
ten minutes. 
