MAGNETIC DECLINATION AT TORONTO, ST. HELENA, AND HOBARTON. 555 
one day on either side of that day. The first table comprised 230 days and the 
second 226 days ; the reason of the number of days falling- short of the full comple- 
ment being the intervention of Sundays, when no observations were recorded. 
Table IV. exhibits in one view the results of these two tables. It does not appear to 
present any satisfactory evidence of the existence of a difference either in the character 
or the amount of the lunar diurnal variation at the periods of the moon’s extreme 
divergence on either side of the equator ; at the same time the number of days (230 
and 226) is too few to furnish positive evidence as to the existence of a small dif- 
ference ; the general character of the variation appears to be the same in both cases, 
when allowance is made for irregularities which must be expected to present them- 
selves in such short periods of comparison. 
Table IV. 
Lunar hours. 
Days of the 
moon’s ex- 
treme north 
declination. 
Days of the 
moon’s ex- 
treme south 
declination. 
Mean of six 
years, Table I. 
Lunar hours. 
Days of the 
moon’s ex- 
treme north 
declination. 
Days of the 
moon’s ex- 
treme south 
declination. 
Mean of six 
years, Table I. 
0 
Scale divisions. 
-•35 
Scale divisions. 
— •35 
Scale divisions. 
-•35 
12 
Scale divisions. 
-•47 
Scale divisions. 
—•31 
Scale divisions. 
-•42 
1 
-•33 
-•17 
-•32 
13 
—•14 
—•28 
-•30 
2 
-•48 
-•10 
—•225 
14 
-•16 
— •28 
-•19 
3 
-•13 
+ •13 
—•14 
15 
-•16 
—•10 
— •12 
4 
-h-OS 
+ •11 
+ •14 
16 
+ •07 
— •04 
+ •03 
5 
+ •18 
-•04 
+•175 
17 
+ •01 
+ •36 
+ •17 
6 
+ •15 
+ •01 
+ •17 
18 
+ •15 
+ •18 
+ •31 
7 
+ •16 
— •03 
+•11 
19 
— 12 
+ •19 
+ •11 
8 
-•01 
+ •10 
+ •01 
20 
+ •14 
+ •08 
+ •06 
9 
00 
+ •07 
-•12 
21 
+ •02 
+ •04 
—•15 
10 
—19 
-•16 
-•30 
22 
— •04 
—•35 
-•35 
11 
-•43 
-•25 
-•43 
23 
—•22 
—38 
—•30 
St. Helena . — The hourly observations at St. Helena, which have been employed in 
this investigation, extended from September 1842 to August 1847, comprehending 
five years. They have been treated in the manner already described in the discus- 
sion of the Toronto observations, with this difference only, that as the magnetic 
disturbances are less in amount at St. Helena, the limits of exclusion on account of 
disturbance were taken at 2*5 scale divisions, or 1''78 in arc. 
The whole number of observations at St. Helena, which have been thus treated, 
amounts to 36,449, of which 2678 have been put aside in consequence of the amount 
of disturbance (measured from the monthly mean at the same hour) equalling or 
exceeding l'-78 in arc. The following Table exhibits the mean variation in the five 
years at the several lunar hours, due to the moon’s influence. The deflections are 
those of the north end of the magnet, and are easterly when the — sign is used, and 
westerly when the -f- sign is used. The value of a scale division at St. Helena 
was 0 '' 71 1 . 
