MAGNETIC OBSERVATIONS. 
149 
OBSERVATIONS—Continued. 
Station, Camp 140, near Marl Springs; latitude 35° 11' 8". 0; longitude Vi. i'2m. 10. 30s. 
Needle, B. Date, March 6, 1854. Hour of beginning, 4 h. 15 m. p. m.; hour of ending, 4A. 45 m. p. m. 
Observer, Lieut. J. C. Ives, Topographical Engineers. 
o > " 
( 82 05 
Needle vertical, face of circle north, reading of azimuth circle__ i 82 05 
( 82 02 
( 82 00 
Needle vertical, face of circle south, reading of azimuth circle... -j 82 02 
( 82 02 
Reading of azimuth circle when plane of instrument is in the magnetic meridian.. 82 02 40 
Reading of azimuth circle when plane of instrument is in the true meridian___ 9G 01 45 
Approximate magnetic declination...... 13 59 05 E. 
OBSERVATIONS FOR MAGNETIC INCLINATION AND INTENSITY—No. 4. 
Face of circle. 
Direct. 
Def. towards 
the vertical. 
( 1 ) 
Def. from the 
vertical. 
12 ) 
Ther. 
Fah. 
Def. with wt. 3 gr. 
Def. towards 
the vertical. 
( 1 ) 
Def. from the 
vertical. 
(2) 
Ther. 
Fah. 
East 
West. 
o ' 
GO 46 
GO 47 
GO 45 
60 47 
60 50 
60 47 
Means. 
60 47 00 
Corr. for index error of needle.. 
Deduced inclination . 
/ a 
8 48 
60 55 48 
Differences , 
Half diff. or angles of deflection. 
Sum of means. 
Half sum — dip.. 
o ' 
94 50 
94 45 
94 45 
94 40 
94 38 
94 40 
o ' 
26 30 
26 28 
26 30 
26 28 
26 30 
26 35 
o 
51 
51 
o ' 
102 55 
102 48 
102 58 
102 45 
102 55 
102 40 
o ' 
18 20 
18 20 
18 15 
18 22 
18 15 
18 10 
j (1) 94 43 00 ) 
| (2) 26 30 10 j 
57 
j (1) 102 50 10 1 
j (2) 18 17 00 j 
68 12 50 
84 33 10 
34 06 25 
O ' " 
42 16 35 
121 13 10 
121 07 10 
60 36 35 
60 33 35 
o 
54 
54 
o 
54 
