145 
of the Terrestrial Magnetic Intensity. 
the morning, the time, nearly, when the sun was on the mag- 
netic meridian ; that it increased from this time until between 
9 and 10 o'clock in the evening ; after which it decreased, and 
continued decreasing during the morning until the time of the 
minimum.” 
c 2. From observations made in the open air. 
Time of Ob- 
servation. 
Mean of the Observations of 
June 20, 21, 22. 
Azimuth of the 
point of Equili- 
brium. 
Terrestrial Mag- 
netic Intensi- 
ty. 
6 h 00 m 
79° 30.0 
1.00112 
7 30 
79 51.7 
1.00061 
9 00 
80 24.7 
1.00028 
10 30 
80 42.2 
1.00000 
Noon. 
80 32.7 
1.00015 
1 30 
79 23.0 
1.00134 
3 00 
78 53.2 
1.00188 
4 30 
78 34.8 
1.00223 
6 00 
78 20.3 
1.00251 
7 30 
78 26.5 
1.00239 
9 00 
78 42.3 
1.00209 
“ F rom these it appears, that the minimum intensity happened 
nearly at the time the sun passed the magnetic meridian, and 
rather later than in May, which was also the case with the time 
of the sun’s passage over the meridian. The intensity increased 
until about 6 o’clock in the afternoon, after which time it ap- 
pears to have decreased during the evening, and to have been 
decreasing from an early hour in the morning. 
' “ The general agreement of these intensities with those de- 
duced from the observations made in-doors, is as near as could 
be expected, considering that an interval of twenty days had 
elapsed between the two sets of observations. From this, and 
the agreement in the manner in which the westerly and easterly 
points of equilibrium approach and recede from the north in 
the two cases, which I have before pointed out, we may con- 
clude, that there is nothing anomalous in the action which takes 
place on the needle under the different circumstances of its be- 
ing placed in-doors or in the open air ; and that the apparent 
anomaly in the directions of the needle in the two cases, which 
VOL. XIV. NO. £7. JANUARY 18^6. K 
