1 1 1
0. (sextant) ( ) 2
1. IB I AB I AI E H H E B GHE CIHE ( ) 2 2 I H A (0 ) ( ) 3
2 2 θ = α + γ β + γ = θ + α β + γ = ( α + γ ) + α β = 2 α + γ γ C H CIG ( ) 4
2. John Hadley 1731 5 ( (octant)) Captain John Campbell 1757 60 ( 1/6) 45 ( 1/8) 3. 1731 18 2 5
3. (1853) 6
7
cf) 1 = 1.8m 1 =10 1 10 9 6 9.6 8
9
1 ( ) =2 ( ) IHE CEH= = CIH IHE =2i 2j =2(i-j) IHD IDH= = IHF HID =i-j 2 2 =(90 j) (90 i) 2 2 2 + 2 2 + 10
3 ( ) ( ) ( ) ( ) ( ) = 90 ( ) + 23.4 ( ) = 90 ( ) 23.4 ( ) ( ) = 90 ( ) + ( ) ( ) = 90 ( ) + ( ) 1485 (noon solar declination table) p2 11