MAGNETIC DIP IN THE UNITED STATES. 303 



Observations repeated ten rods farther north. 



Date. 



Hour. 



Needle. 



No. 



. Readings. 



Dip. 



1841, Oct. 8, 



2—3, P. M. 



No. 1, 





40 



71° 14'.4 



(( 



(( 



No. I, poles reversed, 





40 



6.4 



<( 



(( 



Mean of No. 1, 





80 



10.4 



Mean of both sets of observations, 



• «•••« 





160 



71 10.1 



At the last two stations the dip is materially less than might have been anti- 

 cipated; nevertheless, I consider the observations entitled to as much confi- 

 dence as the others. 



Magnetic Dip at Frasersburgh, Ohio. Latitude 40° 9' N.,- Longitude 82° 8' W. 

 Place of observation near canal lock No. 16. 



Date. 



Hour. 



Needle. 



No. 



Readings. 



Dip. 



1841, Oct. 9, 



10—11, A. M. 



No. 1, 





40. 



71°44'.l 



<( 



n 



No. 1, poles reversed, 





40 



50.2 



(( 



(( 



Mean of No. I, 





80 



47.1 





Observations 



repeated near Canal Lock No. 



17. 







Date. 



Hour. 



Needle. 



No. 



Readings. 



Dip, 



1841, Oct. 9, 



H—5h P. M. 



No. 1, 





40 



71° 54'.3 



(< 



(( 



No. 1, poles reversed. 





40 



46.2 



(( 



(( 



Mean of No. 1, 





80 



50.3 



Mean of both sets of observations, 



. ..... 





160 



71 48.7 



Magnetic Dip at Dover, Ohio. Latitude 40° 33' N.,- Longitude 81° 30' W. 

 Place of observation near canal lock, two miles north of the town. 



Date. 





Hour. 



Needle. 



No. Readings. 





Dip. 



1841, Oct, 



11, 



9—10, A. M. 



No. 1, 



40 



72' 



° 20'.9 







ik 



No. 1, poles reversed. 



40 





18.7 







ii 



Mean of No. 1, 



80 





19.8 







10—11, A. M. 



No. 1, 



40 





16.0 







<( 



No. 1, poles reversed. 



40 





21 .3 





, 



n 



Mean of No. 1, 



80 





18.7 



Mean of both sets of observations, , 



• 



160 



72 



19.2 



Magnetic Dip at Fulton, Ohio. Latitude 40° 55' N.; Longitude 81° 38' W. 

 Place of observation near the canal lock. 



Date. Hour. Needle. 



1841, Oct. 12, 9— 10, A.M. No. 1, 



" " No. 1, poles reversed, 



Mean of No. 1, 

 VIII. — 4 B 



No. Readings. 



Dip. 



40 



72° 40'.4 



40 



37.4 



80 



72 38.9 



