16 
Capt. Parry and Lieut. Foster’s 
fully noted. In the following tables these phenomena, with 
the exception of the temperature, have necessarily been 
omitted, on account of the great length to which their 
insertion would have extended this communication ; but an 
abstract of all the particulars relative to one of the needles, 
No. 2, has been made by Lieutenant Foster, and is given in 
continuation of this series ; diagrams exhibiting graphically 
the various deflections of needle No. 1, for which we are 
indebted to the ingenuity of Mr. Hooper, are also subjoined. 
The original register of the whole is preserved and can 
easily be referred to, should any of the observed phenomena, 
beyond those which are here given, be considered likely to 
have influenced the motion of the needles. As far, however, 
as our own observations extended, we have reason to believe 
that on no occasion were the needles in the slightest degree 
affected, either by the aurora, meteors, or any other percep- 
tible atmospheric phenomenon. 
Soon after the observations were commenced, it was ascer- 
tained that twice in every four and twenty hours the needles 
moved past a certain point, which may be denominated the 
zero, or mean magnetic meridian ; a fact, which was first 
rendered clearly apparent, from the accompanying diagrams 
already mentioned, by which it appears that in every instance 
except one, both needles every day passed the line in ques- 
tion. On a single day, February 24, the needle No. 2 did 
not arrive at it during its eastern motion. 
The means of the times of the needle passing this zero, as 
deduced from four months continued observations, is, 6*15® 
A. M., and 4 h 37 m P. M. ; the mean time in each month being 
as follows : 
