ON THE MAGNETIC INTENSITY OF THE EARTH. 43 
_ vations are wholly wanting; but in all cases the insertion of 
the authorities themselves in the map manifests the degree 
of exactness to which it is yet possible to trace the several 
_ portions of each line. 
Where the geographical positions are too near each other for 
convenient insertion in the map, two or more stations are. 
Ss collected into a group in the table, and the mean latitude, 
_ longitude, and intensity are placed at the foot of the page. 
Such groups are in all cases composed of the determinations 
of the same observer, and the mean determination inserted in 
the map is characterised by an additional figure, placed be- 
neath, expressive of the number of separate stations thus 
represented. 
In the case of stations visited by two or more observers, their 
separate determinations have been inserted in the map 
wherever space has permitted. As this could not always be 
done in the north of Europe and Asia, the mean of the 
. determinations of the two observers has been given, cha- 
racterised by the mark +, expressive of the double weight 
| _ to which such intensities are entitled. 
| The geographical positions may require correction in a few 
| instances, but pains have been taken to obtain them correctly 
. from the most recent authorities. 
Division I. Norruern HEMISPHERE. 
§ 1. Intensities from 1:85 to 1°75. 
Lat. Long. Observer. Date.|| Intensity. 
ee 63 0 |120 O\Due....,......... {1829} 1-759 
Oe 40 43 285 57\Sabine............ 4 1°803 
Sts 65 55 | 87 33)/Hansteen........../|1829]| 1-667 
....| 60 02 | 90 33\Hansteen.......... 1829]| 1-660 
ee 56 16 | 91 00\/Hansteen & Due.... {1828]) 1°654 
me EOL OST 39. 58 27 | 92 11/Hansteen........../1829]| 1°668 
sBV1AA: 56 01 | 92 57/Erman............/1829]) 1:652 
Hgt-At' re »  |Hansteen & Due.... |1829]) 1:663 
55 43 | 96 53.Erman............ 1829]| 1-670 
5 » |Hansteen & Due.. ..|1829]) 1-678 
.s....{ 55 12 | 98 50)/Hansteen & Due.... |1828) 1°671 
AS es RY 55 00 | 99 20\/Hansteen & Due ... |1828)| 1°672 
