MAGNETIC OBSERVATIONS. 115 
OBSERV ATIONS— Continued. 
Station, Camp 132, Rio Colorado ; latitude 349 45' 53".60 ; longitude Th. 31m. 31. 23s. 
Needle, B. Date, February 25, 1854. Hour of beginning, 2h. 50m. p. m.; hour of ending, 3h. 10m. p.m. 
Observer, Lieut J. C. Ives, Topographical Engineers. 
[e] 9 " 
; 19 30 
Needle vertical, face of circle north, reading of azimuth circle 19 28 
19 20 
š 19 20 
1 Needle vertical, face of circle south, reading of azimuth circle 19 30 
; 19 30 
Reading of azimuth circle when plane of instrument is in the magnetic meridian 19 28 00 
Reading of azimuth circle when plane of instrument is in the true meridian 33 03 41 
Approximate magnetic declination 13 35 41 ۰ 
OBSERVATIONS FOR MAGNETIC INCLINATION AND INTENSITY —No. 4. 
1 Def. with wt. 2) gr. | Def. with wt. 3 gr. 
š : | 
Face of circle. Direct. | 
Def. towards | Def. from | Ther. | Def. towards ` Def. Ther. 
the vertical. | the vertical.| Fah. | the vertical. the سب‎ Fah. 
(2) | ( | 2 
| 
6 , 0 , 0 , [e] | o r | [e] , 0 
60 40 94 35 26 25 | 76 | 102 45 | 18 22 76 
East بت کے‎ 60 8 94 30 M de .. us: EZ RM 9 00010 
60 42 94 40 L0 30 Eo | 102 40 | IB ^ 28- 290 
| | 
60 37 94 30 26 TI | 102 35 18- 20 |... 
West 60 37 94 40 میں‎ ۲ mane seer | 102 40 | 18 20 |-------- 
60 40 94 38 26 18 T6 | 102 30 | 18 17 16 
| | | 
e] , ” , ” 0 ; E o 
(1) 94 35 30 ! 1 (1) 102 s 80 } 76 
Means 60 39 00 ] (2) 26 23 00 76 (2) 18 22 00 
D " 
Cor. for index error of needle...| 十 8 48 
Deduced inclination..........- 60 47 48 
o " " [o] , " 
` EEN وو مع‎ ONS E Ely me 16 00 X Jj. 
° , ” 0 , " 
Half diff. or angles of deflection 34 06 15  — [|------- 42 08 25 e 
7 o 4 7 o H 
Sum of means a J uM وی‎ 121 e N89 1... 
[e] , ” o [i m" 
E َٰ یی‎ 09 
Half sum — dip yes B My  Á بھی دب‎ 60 30 25 
