144 MAGNETIC OBSERVATIONS. 
OBSERV ATIONS— Continued. 
Station, Camp 130, Rio Colorado ; latitude 340 36’ 19". 20 $; longitude Th. 37m. 4.365. 
Needle, B. Date, February 23, 1854. Hour of beginning, 3h. 50m. p. m.; hour of ending, 4h. 20m. p. m. 
Observer, Lieut. J. C. Ives, Topographical Engineers. 
[9] , " 
60 10 
Needle vertical, face of circle north, reading of azimuth circle 60 08 
60 05 
60 10 
Needle vertical, face of circle south, reading of azimuth circle S ST 
60 11 
Reading of azimuth circle when plane of instrument is in the magnetic meridian 60 09 00 
Reading of azimuth circle when plane of instrument is in the true meridian 74 00 21 
Approximate magnetic declinati is OF X1 E 
OBSERVATIONS FOR MAGNETIC INCLINATION AND INTENSITY—No. 4. 
e | x Def. with wt. 22 gr. Def. with wt. 3 gr. 
| 
Face of circle. Direct. | > 
| Def. towards, Def. from Ther. | Def. towards | Def. from Ther 
| the vertical. | the vertical. | Fah. | the vertical, | the vertical. | Fah. 
I (2) (1) (2) 
Qt دور‎ D Se o gs (ree o 
60 20 94 25 26 15 76 102 33 1780 76 
East .... 60 20 94 20 اٹ‎ n سے ا‎ a 102 25 27 55 2 ies 
60 22 94 25 35 با ۲ 3 102 ات سس لا‎ DO Ili» 
60 18 94 30 28 "IB Du ul 102 25 17 40 =} cae ماد‎ 
West 60 25 94 25 20 20 o REA AA 102 35 Ho 4 Lll 
60 20 94 20 26 15 76 102 25 17 50 76 
| o , n Oe " [e] 9 , ” 0 
M | (1) 94 24 10 (1) 102 28 50 
— اة‎ 1 (2) 26 17 50 的 7 
| 
| 
| 1 " 
Cor. for index error of needle... 十 8 48 
Go ow 1 
Deduced inclination ----------- 60 29 38 
[o] , ” , " 
Differences e ^W o sS 84 40 مب دا اد وو‎ 
° , , O H " 
Half diff. or angles of deflection. 1. sd 04 10 — [OTT OES Oe E ا اک‎ 
U ° , ” [e] , " 
Sum of means 人 x= 195 cu Oo pe modd LS 
o Fo cH pe S ٥ 7 " 
Half sum — dip Sch bun... |... wu. سیب‎ - 
