62 



RETORT ON 



OBSERVATIONS OF MAGNETIC DECLINATION. 



Magnetic Declination. 

 Gosport, Va. October 30, 1865. 





Circle Readings. 



Reading of Magnet. 





Mean 



359° 59' IS" 



(1) Scale erect . . . 



(2) Scale inverted . 



(7) — (2) = A . . . 



8l a .7 

 76-S 







+ 5-2 



Q 



<L> 



ft 



Transit of Sun's 



O 



H 



1st limb . . . 

 2d limb . . . 



Mean .... 



io h 4o m 6 s . 2 

 42 27.0 





162 12 45 



10 41 16.6 



T3 



Vernier 



Mean 





1st limb . . . 

 2d limb . . . 



Mean .... 



io h 44"* 48 B .o 

 47 8.8 



> 



163° 34' 45" 



10 45 58.4 



ft 



Reading of Magnet. 







OJ 



(1) Scale inverted . 



(2) Scale erect . . . 



(2)-(l) = A . . . 



6 4 d .2 



93-5 





+ 29-3 





Telescope Direct. 



Telescope Reversed. 



Equation of time ..... 

 8 



i6 m 13 s . 7 



— 16° 47' 28" 



—13 S 6 3 6 





Circle reading to magnet .... 

 iX| scale division ..... 



359° 59'-2 



+ 6.1 



339 29.6 





180° + circle reading to sun 



339 '34-9 

 342 12.7 





Magnetic declination . 



2 37.8 W. 





These observations 

 Chronometer o h 4 m 



were made before noon. 

 40 s . 2 fast of local mean time. 



