102 
MAGNETIC OBSERVATIONS. 
OBSERVATIONS—Continued. 
Station , Camp 71, Arch Spring; latitude 35° 04' 45". 10; longitude 7 h. 15 m. 10.39s. 
Needle, B. Date, November 26, 1853. Hour of beginning , ih. 30 m. p. m. ; hour of ending , 5 h. p. m. 
Observer, Lieut. J. C. Ives, Topographcial Engineers. 
Needle vertical, face of circle north, reading of azimuth circle. 
Needle vertical, face of circle^outh, reading of azimuth circle.. 
Reading of azimuth circle when plane of instrument is in the magnetic meridian 
Reading of azimuth circle when plane of instrument is in the true meridian_ 
Approximate magnetic declination__ 
o 
f 
68 
05 
68 
12 
68 
20 
68 
10 
68 
30 
68 
20 
68 
16 
OBSERVATIONS FOR MAGNETIC INCLINATION AND INTENSITY—No. 4. 
Face of circle. 
Direct. 
Def. with wt. 2 gr. 
Def. towards 
the vertical. 
(1) 
o 
( 
o 
I 
61 
48 
87 
30 
61 
50 
87 
40 
61 
50 
87 
25 
61 
47 
87 
35 
61 
45 
87 
45 
61 
40 
87 
50 
o 
/ II 
o 
61 46 40 
( (D 
1 (2) 
87 
35 
/ II 
-j- 8 48 
o 
I // 
Def from the 
vertical. 
(2) 
Ther. 
Fah. 
Def. with wt. 2| gr. 
Def. towards 
the vertical. 
(1) 
Def from the 
vertical. 
( 2 ) 
Ther. 
Fah. 
East. 
West. 
Means. 
Corr. for index error of needle.. 
Deduced inclination .. 
Differences. 
Half diff. or angles of deflection. 
Sum of means.. 
Half sum—dip.. 
o ' 
35 45 
35 50 
35 50 
35 55 
35 58 
35 52 
o 
55 
55 
o ' 
94 10 
94 30 
94 15 
94 25 
94 20 
94 32 
o i 
28 40 
28 25 
28 45 
28 40 
28 55 
28 50 
o 
55 
(1) 94 22 00 
(2) 28 42 30 
61 55 28 
51 45 50 
65 39 30 
25 52 55 
32 49 45 
123 29 10 
123 04 30 
61 44 35 
61 32 15 
o 
55 
55 
o 
55 
Night cloudy ; no observations on Polaris foi declination. 
