MAGNETIC OBSERVATIONS, 
89 
OBSERVATIONS—Continued. 
Station, Camp 61, Isleta; latitude 34° 54' 27". OG; longitude 7 h. 06m. 40s. 
Needle, B. Date, November 9, 1853. Hour of beginning, 4 h. p. m, ; hour of ending, 5h. p. m. 
Observer, Lieut. J. C. Ives, Topographical Engineers. 
o t " 
( 46 44 
Needle vertical, face of circle north, reading of azimuth circle. J 45 47 
1 4G 51 
( 4G 24 
Needle vertical, face of circle south, reading of azimuth circle. J 45 55 
( 4G 46 
Reading of azimuth circle when plane of instrument is in the magnetic meridian. 46 44 30 
Reading of azimuth circle when plane of instrument is in the true meridian. 59 57 55 
Approximate magnetic declination_ 13 13 25 E. 
OBSERVATIONS' FOR MAGNETIC INCLINATION AND INTENSITY—No. 4. 
Face of circle. 
Direct. 
Def. with wt. 1 gr. 
Def. with wt. 2 gr. 
Def. towards 
the vertical. 
( 1 ) 
Def. from 
the vertical. 
( 2 ) 
Tli er. 
Fah. 
Def. towards 
the vertical. 
( 1 ) 
Def. from 
the vertical. 
( 2 ) 
Ther. 
Fah. 
East___| 
0 > 
62 12 
62 15 
62 08 
62 18 
62 21 
62 20 
O ' 
O ' 
O 
O ' 
O ' 
O 
West. i 
49 35 
49 38 
49 37 
74 50 
74 55 
74 58 
36 35 
36 32 
36 28 
87 75 
87 50 
88 08 
Means____ 
55 
53 
O ' " 
62 15 40 
0 ' " 
j (1) 49 36 40 ) 
( (2) 74 54 20 j 
O 
55 
0 ' " 
j (1) 36 31 40 ) 
( (2) 88 04 20 j 
O 
53 
Cor. for index error of needle... 
Deduced inclination_ 
+ 8 48 
O ' " 
25 17 40 
B 
O'" 
51 32 40 
O ' " 
62 24 28 
Differences... 
Half diff. or angles of deflection. 
0 ' " 
12 88 50 
0 ' " 
25 46 20 
Sum of means_ 
0 ' " 
124 31 00 
0 ' " 
124 36 00 
Half sum — dip. 
0 / n 
62 15 30 
0 / 11 
62 18 00 
12 m 
