MAGNETIC OBSERVATIONS. 
OBSERV ATIONS—Continued. 
155 
Station, Cambridge Oi 
Needle, A. Date, May 10. 1854. Hour of beginning, 11h. 30m. a. m. ; hour of ending, 12 m. 
Observers, Prof. W. €. Bond and Lieut. J. C. Ives. 
bservatory ; latitude 420 22' 48" ; 
longitude 4h. 44m. 29.68. 
° , " 
14 52 
Needle vertical, face of circle north, reading of azimuth circle 14 650 
14 45 
14 52 
Needle vertical, face of circle south, reading of azimuth circle 14 50 
EI 14 60 
Reading of azimuth circle when plane of instrument is in t li 14 51 30 
Reading of azimuth circle when plane of instrument is in the in meridian 5 04 00 
Approximate magnetic declination 9 47 30W. 
OBSERVATIONS FOR MAGNETIC INCLINATION AND INTENSITY—No. 2. 
| 
Def. N. 409 from dip. | Def. 8. 409 from dip. 
Face of circle. Direct. Results. 
o , ہے کک‎ 
at 34 25 | at 114 25 | at. 34 25 | at 114 25 
e poros gis au dc py 
74 35 90 30 58 15 91 58 56 55 
East 74 35 90 20 » 20 | 91 60 56 50 74 30 30 | Direct. 
74 30 90 30 58 25 91. 57 56 48 
N.| 74 21 25 
S.| 74 20 05 ۱ سر ران‎ 
74 30 90 0 58 15 91 55 56 30 
"EE 74 28 90 22 58 25 927 58 56 40 
74 25 90 15 58 20 91. 52 “Y 56 38 
° , ” o 2 1 [o] 7 “ 
piii 9 90 22 50 91 56 40 74 24 03 Mean. 
Means. 74 30 30 ye wes Sew 
58 20 00 56 43 30 
i 
x ° ۶ " o 1 “ E las 
Sum of means. 148 42 50 148 40 10 + 15 04 E M error, 
d 
o , tr 0 , ^ 
Half sum — dip + S 35 14 20 5 
o D ¿e o 1 ” 
DERO eech 82 0% -60 86 BD B 
i ° , ” ° , m 0 1 a 
Half diff. — angles of deflection. 16 01 25 17 36 35 74 39 07 True inclination. 
