MAGNETIC OBSERVATIONS. 
105 
OBSERVATIONS—Continued. 
Station, Camp 73, Jacob’s Well; latitude 35° 03' 53".49 ; longitude 111. lGm. 56.38s. 
Needle, B. Date, November 29, 1853. Hour of beginning, 5 h. 40m. p. m. ; hour of ending, GA. 20m. p. m. 
Observer, Lieut. J. C. Ives, Topographical Engineers. 
O ' " 
f 69 30 
Needle vertical, face of circle north, reading of azimuth circle.69 32 
(. 69 48 
f 69 40 
Needle vertical, face of circle south, reading of azimuth circle.69 32 
( 69 50 
Reading of azimuth circle when plane of instrument is in the magnetic meridian_ 69 38 40 
Reading of azimuth circle when plane of instrument is in the true meridian_ 83 22 21 
Approximate magnetic declination___ 13 43 41 E. 
OBSERVA'ftONS FOE MAGNETIC INCLINATION AND INTENSITY—No. 4. 
Face of circle. 
Direct. 
Def. with wt. 2 gr. 
Def. towards 
the vertical. 
(1) 
Def. from the 
the vertical. 
(2) 
Tlier. 
Fall. 
Def. with wt. 21 gr. 
Def. towards 
the vertical. 
(1) 
Def. from the 
the vertical. 
( 2 ) 
Tlier. 
Fah. 
East. 
West. 
o ' 
61 50 
61 55 
61 50 
61 50 
61 45 
61 55 
o ' 
87 50 
87 45 
87 55 
87 50 
87 45 
87 45 
o ' 
35 30 
35 35 
35 36 
35 50 
35 40 
35 35 
o 
43 
40 
o ' 
94 18 
94 20 
94 10 
94 25 
94 30 
94 35 
o ' 
28 35 
28 40 
28 32 
28 35 
28 30 
28 40 
Means 
Corr. for index error of needle . . 
Deduced inclination 
61 50 50 
+ 8 48 
o ' " 
61 59 38 
Differences 
Half diff. or angles of deflection 
Sum of means 
Half sum =: dip 
(1) 87 48 20 
(2) 35 37 40 
o ' " 
52 10 40 
o / n 
26 05 20 
o > // 
123 26 00 
o / n 
61 43 00 
} 41 - 6 { 
(1) 94 23 00 
(2) 28 35 20 
0/0 
65 47 40 
o < " 
32 53 50 
o ' " 
122 58 20 
O'" 
61 29 10 
14 m 
