= 4 
. Terrestrial Sapiniaee . a 
No. 15. Vincennes, Indiana, Lat. 38° 43! N., Lon. 87° 25! W. Sept. 18, 1840, 
x 
Needle No.1. B North. "Wendie No. a) A Nee 
Face of in-| Faceof | Face of in-| Face of 
strument. | needle. Dip indicated. strument.| needle. Dip indicated. 
E. E, 71°10/.5 E E 69°52’ 
Ww. w. 68 25 Ww w. | 69 40.5 
Ww. E. 71 06 Ww E. | 69 52.5 
E. Ww. 68 31.5 E w. 69 50 
A North. B North. 
E. E. 68 46.5 E. E. 69 56.5 
Ww. w. 71 w. Ww. | 69 56 
w. E. 68 36 we E. 9 50 
E. w. 1 E. w. 9 63 ee 
: 8)558 50 | 8)559 00.5 
Mean, 69 51.25 | © Mean, 69 52.56 
No. 16. Paoli, Indiana, Lat, 38° 35! N., Lon. 86° 25' W. Sept. 20, 1840. 
ks dl .1. A North. | eedle No. 2. orth. 
ace of in-| Face of Face of in-| Face of | : 
strument. _needile, Dip indicated. bytrantent needle. Dip indicated. 
i & 8°30 E. E 69°30’ 
Ww. w. 70 A7.5 w. w 69 26,0 ... 
Ww. E. 68 30 w. E 69 34.5 
E. | > w. 70 45.5 5. Ww 69 25 
B North. B North 
E. E. 70 47 a 9 37 
w. w. 68 12 w w. 69 41.5 
W. E. 70 49 w E. 69 39.5 
E. w. 68 21 E. w. 69 51.5 
8)556 42 By556 45.5 
Mean, 69 35.25 Mean, 69,3568 _ 
The dose ne ne of the results of these two needles, will 
undoubtedly surprise experimenters on magnetism. ‘They are 
much nearer to identity than at first I had hoped to bring them. 
The desirable object has been accomplished partly by a fine in- 
strument, and partly by peculiar manipulations, which, wh? 
have perfected, I shall communicate to the: public. 
