MAGNETIC OBSERVATIONS. 153 
OBSERV ATIONS— Continued. 
Station, Cambridge Observatory, Mass.; latitude 42° 22! 48 ; longitude 4h. 44h. 29. 6s. 
Needle, B. Date, May 10, 1854. Hour of beginning, 10h. a. m. ; hour of ending, 11h. a. m. 
Observers, Professor W. C. Bond and Lieut. J. C. Ives. 
. ° , i 
à : f l4 48 
Needle vertical, face of circle north, reading of azimuth circle 14 48 
C Hu 
14 47 
Needle vertical, face of circle south, reading of azimuth circle 14 52 
۰ 14 46 
Reading of azimuth circle when plane of instrument is in the magnetic meridian...........---.--- 14 49 20 
Reading of azimuth circle when plane of instrument is in the true meridian 5 04 
9 45 20 ۰ 
y H à EE 
Approximate mag t 
ORSERVATIONS FOR MAGNETIC INCLINATION AND INTENSITY—No. 2. 
Def. N. 409 from dip. | Def. 8. 400 from dip. 
Face of circle. Direct. Results. 
o E 0 r 0 , 0 1 
at 34 25 |atll4 25 | at 34 25 lat 114 25 
0 H / o 1 0 1 ° 1 0 7 7 
74 28 | 90 45 | 67 45 | 91 40 | 56 45 a 
East 74 25 | 90 55 | 57 48 | 91 45 | 56 40 1۵ 3۴ ہے‎ |». 
74 21 | 90 50 | 57 50 | 91 40 | 56 45 ا تا ے‎ i 
° S. | 74 15 40 [By — 
74 22 | 90 40 | 57 50 | 91 45 | 56 55 
Wa کت تی‎ 74 28 | 90 45 | 57 50 | 91 40 | 56 50 
74 25 | 90 45 | 57 52 1 48 | 56 55 
o 1 2 [e] 7 H o 7 
ہے ریم‎ 90 46 40 91 43 00 T4 19 28 | Mean. 
Mis us od 74 24 50 
57 49 10 56 48 20 
o 1 “ o ' tr 
Sum of means 148 35 60 148 31 20 
1 véi 
o 1 Hi o , " 3 
Half sum 一 dip 74 17 5 74 15 40 |“ 十 8 48 [3 ¿Index error. 
E | 
o r وو‎ gl ° , ” J 
TEE 85 BE . 30 34 54 40 
o 1 " o , " o EU ou 
Half diff. — angles of deflection -| 16 28 45 17 397. 20 74 28 16 | Trueinclination, 
Seege 
20m 
