182 



REPORT ON 



Computation oi 



Coefficients A v D 



v E 1( from Deviations observed on 32 Points. 





I. 



II. 



Lower 

 Half of 

 Table A, 

 Col. III. 



III. 



Half Sum 



of 



Quantities 



in Cols. I 



and II. 



Constant 



Part of 



Deviation. 



IV. 



Half Sum 

 of Cols. I 



and II, 

 (changing 



Signs of 

 Col. II.) 



Quadrantal 

 Deviation. 



V. 



Computation 

 of D,. 



VI. 



Computation 

 of E,. 





Upper 

 Half of 

 Table A, 

 Col. III. 



3. 

 1 



Products of 

 Col. IV by 

 Multipliers. 





Products of 

 Col. IV by 

 Multipliers. 





4- 1° 40' 



4-2 20 

 + 2 20 

 + 2 3 



4- 1° 40' 

 + 1 30 

 4-1 20 

 4-i 10 



4-0 40 



+ 45 

 4- 1 



+ 1 15 



4- i° 40' 

 + 1 55 

 4- 1 50 

 + 1 50 



+ 1 3° 



4- 1 27 



+ 1 35 

 + 1 35 



0° 0' 

 4-0 25 

 4-0 30 

 4-0 40 



4-0 50 

 + ° 43 

 + 35 



4-0 20 







s. 

 s 6 



0° 0' 

 4- 10 

 4- 21 

 4-0 37 



1 



s, 



s 2 



o° 0' 

 4-0 23 



4- 21 

 + 15 





4-2 20 



4-2 IO 

 4-2 IO 



+ 1 55 



I 



s< 

 s 2 



+ 50 



4- 40 



+ 25 

 4-0 8 







-s 2 



— D 6 







— 0' 16 



— 25 



— 18 





Sum of 4- terms = 4- 

 Sum of — terms = — 



Divisor 8 



13 22 



Sum of 4~ t 

 Sum of — t 



Divisor . 



] 



:rms = 4-3 1 1 

 ;rms = — 



+ 



4 

 E,= 



59 

 59 





4- 13 22 



| + 3 " 





 = 0.0 







A,== 



4-1 40.2 



D 1= 4-o 47-8 





Note.— S, = . 195. S 2 =. 3 8 3 . S 3 =.ss6. S 4 = .7o7. S 6 



31. S 6 = .Q24. S,= 



The resulting values of the coefficients for each compass, at each station, are 

 given in the following tables : 



Coefficients of the Deviations of the Admiralty Standard Compass. 



STATION. 



DATE. 



Ax 



Br 



c, 



Di 



E, 



Hampton Roads . . . 



November 1, 1865 



+ i° 37'-4 



4- 9° 4'- 6 



— o°33'.i 



4- o° 29'. 2 



— 0° 7'-S 



St. Thomas 







November 18, 1865 



4- 14.6 



+ 5 45-5 



+ 33'5 



4-0 3.2 



— 4S.2 



Bahia . 









December 30, 1865 



4- 1 40.2 



+ 3 38-5 



4-0 



4 



+ 47 



8 



0.0 



Monte Video 









January 24, 1866 



4- 1 32-8 



+ 3 4-8 



+ 5 



8 



+ 1 19 



.1 



+ 14-5 



Sandy Point 









February 10, 1866 



+ 35-9 



4-1 20.6 



— 40 



6 



+ S3 



5 



4-0 1.5 



Valparaiso . 









April 4, 1866 



+ 35-6 



4-i 20.2 



— 6 



9 



+ 54 



2 



— 10.2 



Callao . 









April 29, 1 866 



4-0 9.1 



4- 2 21. 1 



— 1 



8 



+ 52 



5 



+ 5.8 



Panama 









May 20, 1866 



4-0 31.6 



+ 3 2.1 



+ 1 



9 



+ 55 



0. 



4- 8.0 



Acapulco . 









June 1, 1866 



— 36.9 



+ 2 45.4 



+ 5 



5 



+ 56 



8 



4-0 8.0 



San Francisco 









June 23, 1866 



— 39.6 



+ 4 53-2 



— 1 15-4 



4-0 51.2 



4-0 5.8 



Coefficients of the Deviations of the After Binnacle Compass. 



STATION. 



DATE. 



A, 



B i 



Cr 



D> 



E, 



Hampton Roads . . . 



November 1, 1865 



+ 0° 27'. 5 



4- 7 i6'.8 



— 1° 14'. 1 



4- i° 39'-2 



4-o° 6'. 2 



St. Thomas 







November 18, 1865 













Bahia . 









December 30, 1865 



4- 1 29.8 



4- 5 43-6 



— 6.9 



4- 1 4i-5 



4-0 7-8 



Monte Video 









January 24, 1866 



+ 1 31 



+ 5 30-6 



4- 41.9 



4- 1 57 



5 



— 42.5 



Sandy Point 









February 10, 1866 



— 24.5 



+ 5 44-4 



— o 14.6 



4- 1 58 



5 



4- 0.2 



Valparaiso . 









April 4, 1866 



4- 4.9 



4-3 58-8 



4- 7.9 



+ 2 1 



5 



— 0.2 



Callao . 









April 29, 1866 



— 27.1 



4-4 12.5 



— 3-9 



4-2 7 



5 



4-0 9.0 



Panama . . 









May 20, 1 866 



— 50.0 



4-3 19-5 



4- 22.0 



4-2 32 



7 



— 18.0 



Acapulco . 









June 1, 1866 



— 1 0.2 



4- 3 4-4 



— 17. 1 



4-2 15 



2 



— 17.2 



San Francisco .... 



June 23, 1866 



— 35.2 



4- 3 28.2 



— 2 13-9 



4- 1 47-5 



4- 10.2 



