MAGNETIC DIPS IN THE UNITED STATES. 



105 



Magnetic Dip at West Point, New York. Latilude 41° 25' N.; Longitude 4h. 56m. TV. 

 Place of observation on the bank of the river, near the steam-boat landing. 



Date. 





Hour. 



Needle. 



No 



Readings. 





Dip. 



1839, Sept. 



5th, 



3—5, 



P.M. 



No. 1, 





40 



73 



' 28'.9 











No. 1, poles reversed, 





40 





27 .7 











Mean of No. 1, 





80 





28.3 











No. 2, 





40 





22.8 











No. 2, poles reversed. 





40 





30.0 











Mean of No. 2, 





80 





26.4 











Mean of both needles. 





160 



73 



27.4 



Magnetic Dip at New York City. Latitude 40° 43' N.; Longitude 4h. 56m. W. 

 Place of observation the yard in front of Colnmbia College. 



Date. 



Hour. 



Needle. 



No 



Readings. 





Dip. 



1839, Sept. 9th, 



8— 10^, A. M. 



No. 1, 





40 



72< 



' 54'.8 







No. 1, poles reversed, 





40 





47.1 







Mean of No. 1, 





80 





50.9 







No. 2, 





40 





47.1 







No. 2, poles reversed. 





40 





59.9 







Mean of No. 2, 





80 





53.5 







Mean of both needles, 





160 



72 



52.2 



Magnetic Dip at New Haven, Connecticut. Latitude 41° 18' iV.,- Longitude ih. 52m. W. 



Place of observation the burial ground. 





Date. 





Hour. 



Needle. 



No 



Readings. 





Dip. 



83( 



), Sept. 



11th, 



7—9, A. M. 



No. 1, 





40 



73' 



" 24'. 







<( 





No. 1, poles reversed, 





40 





34.6 







tt 





Mean of No. 1, 





80 





29.3 







(> 





No. 2, 





40 





14.4 







(( 





No. 2, poles reversed. 





40 





33.9 







(( 





Mean of No. 2, 





80 





24.1 







(( 



i< a, 



Mean of both needles. 





160 



73 



26.7 



VII. — 2 B 



