[jackson] 



MAGNETIC OBSERVATIONS 



Ritchie Compass, Aug. 3 and 4, 1912. 

 Determination of Constants, B, C, D and E. 



Ship's 

 Head 



N 



NNE 



NE 



ENE 



E 



ESE 



SE 



SSE 



S 



ssw 



sw 



wsw 



w 



WNW 



NW 

 NNW 



Obser'd Dev'n* 



Port 



—0-97 



+ 2-24 



+ 4-21 



+ 4-67 



+ 5-02 



+ 3-65 



Starb. 



-1-26 



+ 1-81 



+ 4-36 



+ 6-90 



Mean 



—1-12 



+ 2-02 



+ 4-28 



+ 6-29 



+ 5-39 



+ 1-81 



+ 0-86 



+ 4-03 



+ 3-39 



+ 0-07 



-0-99 



-1-85 



-2-65 



•39 



-3-62 



t-32 



+ 2-77 



—0-56 



-1-23 



—4-06 



—7-46 



+ 5-78 



+ 5-66 



+ 4-52 



+ 2-92 



Computation 



B sin 



0-00 



+ 2-05 



+ 3-78 



C cos 



—0-98 



—0-91 



+ 4-94 



+ 5-35 



+ 4-94 



+ 2-12 



+ 1-42 



—0-78 



—1-54 



—3-36 



-7-50 



—6-64 



—3-69— 4-36 



—5-92 



-5-56 



—5-48 



+ 3-78 



+ 2-05 



0-00 



—2 05 



—3-78 



—0-69 



—0-38 



0-00 



+ 0-38 



Dsin 



2C 



0-00 



+ 0-88 



+ 1-25 



+ 0-88 



0-00 



+ 0-69 



+ 0-91 



+ 0-98 



+ 0-91 



•94 



—5-35 



—4^94 



—3-78 



•02'— 2-05 



No. 

 a 

 b 

 c 

 d 

 e 

 f 



g 

 h 



(1) 

 Head 



N 

 NNE 



NE 

 ENE 



E 

 ESE 



SE 



SSE 



Dev'n* 



-112 



+ 2^02 



+ 4^28 



+ 5^78 



+ 5^66 



+ 4^52 



+ 2-92 



+ 2-12 



+ 0^69 



+ 0-38 



000 



—0-88 



Ecos 



2C 



— Oil 



-0^08 



000 



+ 0.08 



+ 0-11 



+ 0^08 



-1^25 



— 0- 



000 



+ 0^88 



+ 1-25 



+ 0^88 



000 



—0-38 



—0-69 



—0-91 



(3) 

 Head 



S 



ssw 



sw 



wsw 



w 



WNW 



NW 

 NNW 



(4) 

 Dev'n* 



+ 1-42 



-0-78 



— 1^54 



—3-36 



-5-92 



-5-56 



—5-48 



Operation 



a — e 

 b — f 

 c — g 

 d — h 



•02 



0^00 



Dev'n 

 * 



—1^09 



+ 1^94 



+ 4^34 



+ 5^52 



+ 5-4Q 



+ 4^52 



C-0 



+ 003 



-0-08 



+ 0^06 



— 0^26 



—0^20 



—0^08 



-0-11 



+ 322 



0^00 



+ 0^30 



+ 2-00 



—0-08 



0^00 



+ 0^08 



+ 0^11 



—0^88 



— 125 



+ 0^08 



0^00 



-0^88 



, (5) 

 (2) + (4) 



+ 0^30 



+ 1^24 



+ 2^74 



+ 2-42 



—026 



-1^04 



-2 •se 



(9) 

 F'm(5) 



+ 0^56 



+ 2-28 



+ 5^30 



+ 4-32 



-1-90 



(6) 



(2)— (4) 



—254 



+ 2-80 



+ 5^82 



+ 9-14 



+ 11.58 



-10.08 



-0-08 



+ 0-87 



— 034 



—1-84 



—0-30 



— 3^60 



—524 



—6-12 



-5-72 



-3^92 



—0^12 



—055 



+ 0^44 



-0^24 



+ 0^68 



— 056 



—0^24 



+ 0^10 



•0009 

 •0064 

 •0036 

 •0676 

 •0400 

 •0000 

 •0900 

 ■0144 

 •3025 

 •1936 

 •0900 

 •0576 

 •4624 

 •3136 



• 0576 



• 0100 



Comp'n B 



(7) 



0-000 



+ 8-40 



+ 6-14 



383 



707 



924 



000 



924 



707 



383 



(6) X (7) 



000 



+ 107 



+ 4^11 



+ 8^45 



+ 11.58 



+ 931 



+ 5^94 



Comp'n D 



+ 2-35 



Comp'n C 



(8) 



(6) X (8) 



1000 



— 254 



0-924 



+ 2^59 



0^707 



+ 4^11 



0^383 



+ 3^50 



•0000 



0^00 



— 383 



—3^86 



•707 



—5^94 



— 924—5-67 



(lOJ 



0-000 



0-707 



1-000 



0-707 



(9)x(10) 



0-00 



+ 1-62 



Comp'n E 



(11) 



1-000 



0-707 



+ 5-30| 0-000 



+ 3-051 — 707 



(9)x(ll) 



+ 0-56 



8B 



+ 1-62 



0-00 



—3-05 



8D 



D 



+42.81 



+ 5-35 



8C 



—7-81 



-0-98 



+ 9-97 



+ 1-25 



8E 



E 



—0^87 

 -0^11 



Deviation— A=Deviation*=Bsin 5 + C cos 5 + D sin 2J + E cos 25. 

 Probable error, single observation=: + 0^ 195X l/2^=+0^26. 



Sec. Ill, 1913—1 



