114 Dip and Variation of the Magnetic Needle. 
Taste XI.—27 Stations. 
Station. Latitude. , Longitnde. }, Variation. Date. | Differ’nces 
Prairie du Chien, 43° 3/ | 90°53' |—9° 5’ | 1840 = 
Madison, 45 39199 1 | 7 “ 38 - 
43 3 | 89 421 °8 20 ” +8" 
Campbell’s, 43 1 | 89 26| 8 48 ae —31. 
Blue Mounds, 43 0 | 89 36] 8 38 —13 
Trout Brook, 42 59 | 90 45| 9 O “ + 7 
Parish’s 42.58 |.90 10} 8 55 _ —10 
Mineral Point, + 42 51 | 89 8 40 s ett 
Turkey oobi 42°42 |'90 48; 9 0 ‘wi “eS 
Log Hous 42 38 | 90 43) 9 0 ¢ + 3% 
Sherald's Mois _ | 42.35 | 90 = 8 10 = a 4 
Little M wath | 42 31.; 90 31) 8 30 = 2 
weet “| 42 29 | 90.23} 8°92 = +25 
Galena, 42 28 | 90 13) 9 25 % — 4 
\erwood’s, | 42 27 | 90:87.) 9.0.) « BO} 
North branch Mahoqueta,| 42 23 | 90 52| 9 35 | « —45 
itewater, 42:18 | 90°38} 910 | « —15 
Mahoqueta, 42 14 | 90 57 | 8 45 se +22 
armer’s Creck, 42.13 | 9023} 9.8 | « —24 
heney’s, ‘| 4212/9021] 9 5 | « | 98 
Mill, * 1'42-40'}°90 87 }- 9 15 | ee . P98 
Bridge 42. 6 POR} 24 O20 Sh Ae TD 
Small mill, 42. 4)91. 24:9 9% +0 = 
Elkford 42 0); 90 52}; 9 15 eae oe t 
Iron ore, 41 55 | 90 40} 8 20 = . 
Wapsipinnicon, 41 45 | 90 23 8 22 “| +16 
Lost Grove, 41 39 | 90 91-8 10 + +18 | 
Central position, latitude 42° 28’ .N., longitude 90° 25’ W., 
d= —1°.8046, i.e, ~8° 483, c= — 00344, y= 014564, 
Mean of the differences at ten northern stations +1’, 1; seven- 
teen southern —0’.7 ; seven stations having the srrentine com- 
wees variation +-0'.1; six least +2.7; fourteen intermediate 
Taste XU.—11 Stations. 
Longitude,| _ Variation. 
88? 30 | — 5? 37° 
68°34 1 5 34° 
89 49 6 338 
91.22} 8 33°" 
86. - 8.29 % 
{84 38) 11 | 
papas pigs | 
Se 40 Fs a a2: 4 
‘88501 0 9. 
