Terrestrial Magnetism. 
No. 1. Davenport, Iowa Territory, Sept. 15, 1839. Lat. 41° 30’ V., Lon, 90° 18! W. 
322 
Ne dle No. 1. B North. 
“C2 ui u. | Face of 
strument. | needle. Dip indicated, 
E. E. 72°0 
w. w. 70 AZ 
w. E. 72 AT 
E. w. 71 06 
A Nort 
E. E. 70 59 
Wyck Wi 72 52 
Ww. ¥. 70 53 
E. w. 72 57 
8)574 | 16 
Mean, 71 4825 — 
Needle No. 2. B North. 
Face of in-[ Face of 
strument.| needle. Dip indicated. 
E. 58’ 
Ww. 72 02 
Ww. E. 71 54 
E w. 72 03 
A North. 
E E. 72 16 
Ww. w. 71 26 
Ww E. 72 12.5 
E w. 71 28.5 5 
8)57 75 5 OO... 
Mean, 71 : ea 
No. 2. Davenport, Iowa Territory, Sept. 18, 1839. 
[Needle No. 1. B North. } Needle No. 2. A North. 
Face of in-| Face of Face of in-- Face of 
strument.| needle. | Dip indicated. __| strument. needle. D'p indicated. 
E. E. 73° E. E. 72° 18' 
w. w. 70 43 w. Ww. 71 26 
w. E. 72 51 Ww E. 72 14 
E. w. 70 40 EB). }.W. 71 25 
A North. B North 
E. E. 70 57 E. 71 Al 
ee. w. 73 14 w. Ww. 72 19 
ww. of". 70 50 w. E. Ti 30 
ees a oF 73 04 Ek. w. 72 27 
= fepTeer | “8)575 20 
Mean, 71 55.5 | "Mean, 71 55 
No. 3. Lost Grove, (lowa,) Sept. 23, 1839. Lat. 41° 39! W., Lon. 90° 09! W. 
Needle No. 1. A North. Needle No. 2. B North. 
‘ace of in-| Face of Face of Face of 
strument.| needle. | Dip indicated. rsaroat De f needle. Dip indicated. 
E. 71°43’ 
w. 72 36 
E. 71 45 
w. 39 
A North 
E. il 
Ww. 71 34 
E. 72 05 
Ww, 71 44 
8)576 17 
Mean, 72 02.125 
