Dip and Variation of the Magnetic Needle. 



Ill 



Central position, latitude 43° 49' N., longitude 84° A! W., 

 <y=2°.3429, i. e. -2° 20^6, ^= + .00472, y= + . 02429. Mean 

 of the differences at the ten most northern stations - 4''.0 ; nine 

 southern +4'.4; five eastern +2''.l; four western — IM ; ten 

 intermediate + 0'.4. 



Central position, latitude 40° 53' N., longitude 81° 2' W., 6= 

 ° 60404, i. e. -36'.2, a;--= + .00676, ?/ = +.01648. Mean of the 

 differences at the eight most northern stations +3M ; eight most 

 southern — 3M ; three most eastern —V.3', four western — 3'.7; 

 nine intermediate +2M. 



