4 OBSERVATIONS TO DETERMINE THE MAGNETIC DIP 



Magnetic Dip at Hudson, Ohio. Latitude 41° 15' N.; Longitude 81° 24' W. 

 The place of observation was the college yard, distant several rods from the 

 buildings, and the instrument was placed upon a solid block of wood, which 

 was due north from the transit instrument of the observatory. 



Date. Hour. Needle. No. Readings. Observed Dip. 



1838, Sept. 4 11— 12, A. M. No. 2 16 72° 54'-3 



5 5—6, P. M. 1 16 40 -5 



6 11— 12, A.M. 1 16 54-3 



6 «< «i 11 2 16 34*8 



7 11—12, A.M. 1 , 16 57 '2 

 20 10— 11, A.M. 2 16 48-1 



Mean of 96 observations in September, 1838, 72 48 -2 



1839, April 6 4—5, P. M. 1 80 72 46 -9 



26 9— 11, A.M. 2 80 46-5 



27 9— II, A.M. I 80 44-3 

 May 1 9— 11, A.M. 2 80 49-4 



Mean of 320 observations in April and May, 1839, 72 46 -8 



Magnetic Dip at Cleveland, Ohio. Latitude 41° 30' N.; Longitude 81° 51' W. 

 The place of observation was by the Lake shore, nearly in front of the Ame- 

 rican Hotel. 



Date. Hour. Needle. No. Readings. Observed Dip. 



1839, May 9, 8— 12, A. M. No. 1 80 73° 2r-2 



" " " 2 80 30 -8 



Mean of 160 observations M'ith two needles, 73 26 -0 



Magnetic Dip at Detroit, Michigan. Latitude 42° 19' N.; Longitude 83° 3' W. 



The place of observation was an open area west of the city, and not far from 

 the Michigan Exchange. 



Date. Hour. 



1839, May II, 2— 6, P. M. 



'< (I (( (( 



Mean of 160 observations with two needles. 



Needle. 



No. Readings. 



Observed Dip 



No. 1 



80 



73° 37'-2 



2 

 • • • « 



80 



48-1 

 . 73 42 -6 



