AT VAN RENSSELAER HARBOR. 



25 



Determination of June 14. Magnet I. 10. Mirror facing magnetic north. 



Magnetic south meridian. 



I. 317 10' I. 



at 5 h 12 m Gr. t. 



09 II. 



II. 317 02 

 01 



317 05.5 



Mark. 



338 04' 

 02 



338 09 

 08 



338 05.8 



Mean reading on mark . 

 Astronomical bearing (N.) 



Reading of true meridian 

 Reading of magnetic meridian 



Declination . 



. 338 06' 

 . 93 29 E. 



. 244 37 

 . 137 05 



. 107 32' 

 W. at O h 29 m P. M. local time. 



The magnet showed considerable agitation during the day. 



Determination of June 26. Mirror facing magnetic north. 



Magnetic south meridian. 



I. 315 49' 

 47 



II. 316 18 

 17 



Means 316 02.7 

 at l h 3 m P. M. local time. 



Mark reads . 

 Astronomical bearing (N.) 



N. meridian (true) 

 Magnetic meridian 



Declination 



Magnetic south meridian. 



I. 315 52' 

 50 

 II. 315 40 



38 



315 45.0 

 at 2 h O m P. M. local time 



. 338 21' 

 93 29 E. 



244 52 

 135 53 



. 108 59' 

 W. at l h 31 m P. M. 



Resulting mean declination (for June 16) 108 22' W. ; if we omit the 2d determination on account 

 of disturbance, and apply a correction for diurnal change to the mean of the first and last determination, 

 we find 108 12' W. 



