102 
MAGNETIC OBSERVATIONS. 
OBSERV ATIONS— Continued. 
Station, Camp 71, Arch Spring ; latitude 350 04 45". 10 ; longitude Th. 15m. 10. 39s. 
Needle, B. Date, November 26, 1853. Hour of beginning, 4h. 30m. p. m. ; hour of ending, 5h. p. m. 
Observer, Lieut. J. C. lves, Topographcial Engineers. 
Needle vertical, face of circle north, reading of azimuth circle 
Needle vertical, face of circle south, reading of azimuth circle 
Reading of azimuth circle when plane of instrument is in th 
41,22 
mi) 
Reading of azimuth circle when plane of instrument is in the true meridian 
Approximate magnetic declination 
OBSERVATIONS FOR MAGNETIC INCLINATION AND INTENSITY—No. 4. 
Def. with wt. 2 gr. 
Def. with wt. 23 gr. 
Face of circle. Direct. | 
Def. towards | Def from the | Ther Def. towards | Def from the | Ther. 
the vertical. vertical. Fah the vertical. | vertical. ah. 
1) 9 رم‎ | 9 
o 4 o Li O 7 ° ° , ° f ° 
61 48 87 30 35 45 55 94 10 28 40 55 
East 61 50 87 40 85 458 ^ 5008 94 30 18 25^ کو ھا‎ 
61 50, 87 25 qq 0 EFT a و گا سے‎ 94 15 28. dB ای ان‎ 
61 47 87... 95 Bb. SD AO 8 94 25 وہ‎ : Nes ue 
West 61 45 87 45 D DE ee 94 20 3285 OB "TS EO 
61 40 87 50 35 2 55 94 32 28 50 55 
@ ۾‎ “ ° , Hu [e] o 4 + o 
(1). 7 0 (1 94 22 0 
Meons..... 61 46 40 1 (2) 35 51 40 (2) 28 42 30 " 
7 dé 
Corr. for index error of needle..| + 8.48 
Oc 7 
Deduced inclination ........... 61 55 28 
o e: o 4 “ 
Differences 51 45 50  |-------- 65. 39 30 
o 7 dr [e] 4 7 
Half diff. or angles of deflecti 28 BE 0. - LLLI Sb 49 45 — bL. 
, dd o 4 " 
Sum of means 123 -39 — A48 | 1L us 1385 QE DO. di 
o 4 o 4 dt 
Half sum 一 dip 5 Uu “£ 35 L| E > 1 ے٠‎ hosce 
Night cloudy ; no observations on Polaris for declination. 
