MAGNETIC OBSERVATIONS. 



Ill 



Recapitulation of Observed Dips. Observations by H. G. Radcliff. 



No. 



Locality. Latitude. 



Longitude. 



Dip. 



Date. 



1 

 2 

 8 

 4 

 5 

 6 



Port Foulke, Smith Strait .... 

 Littleton Island, Smith Strait . . 

 Gale Point Cadogan Inlet .... 

 Haklayt Island, off Whale Sound . 



Netlik, Whale Sound 



Godhavn, Disco Island, Greenland- . 



78° 18' 

 78 22 

 78 11 

 77 23 

 77 08 

 69 12 



73° 00' 

 73 30 

 76 28 

 73 10 

 71 22 

 53 28 



85° 02' 



84 43 



85 21 

 85 00 

 84 58 

 81 51 



July, 



It 

 August, 



Aug. and Sept. 



1861 



1861 

 1861 



To the above material available for the construction of an isoclinal chart of the 

 vicinity of Smith Strait, I have added the following three determinations from Dr. 

 Kane's expedition: Cape GrinneU,^ latitude 78° 34', longitude, 71° 34', dip 85° 08' 

 in August, 1853. Marshall Bay ,2 latitude 78° 51', longitude Q8° 54', dip 84° 49' 

 in September, 1853. Van Eensselaer Harbor, latitude 78° 37', longitude 70° 53', 

 dip 84° 46' in Jime, 1854. 



The observed inclination / at these eight stations is represented by the equation — 

 /= 84°.97 —0.09 A^ + 0.12 A;i cos ^ 

 where A^=^ —78°. 18 and A^ = 2. —72°. 36 



The isoclinal lines on the chart were computed by the above formula ; as in the 

 case of the declinations and horizontal force determinations, the effect of the secular 

 change between the interval of the two expeditions has been neglected. 



The observations are represented as follows : — 





Observed 1. 



Computed I. 



Difference. 



Port Foulke 



85.003 



84°. 98 



+ 0.O05 



Littleton Island 









84.72 



84.98 



—0.26 



Gale Point 









85.35 



85.07 



+ 0.28 



Hakluyt Island . 









85.00 



85.06 



—0.06 



Netlik 









84.97 



85.04 



—0.07 



Cape Grinnell . 









85.13 



84.92 



+ 0.21 



Marshall Bay . 









84.82 



84.83 



—0.01 



Van Rensselaer Harbor 









84.77 



84.90 



—0.13 



The probable error of any single representation is ±0°.13, and of the resulting 

 lines +0°.05 nearly. 



The chart embodies the collective results for magnetic distribution at and near 

 Smith Strait by the two American Polar Expeditions, and the years 1861, 1858, 

 and 1858, may be taken for the respective epochs to which the graphical represen- 



* Called " Bedevilled Reach" in the magnetic paper, and in the original record ; it pparently com- 

 prised the coast between Capes Inglefield and Ingersoll. See chart in Vol. I of his narrative. See 

 also Smithsonian Contributions to Knowledge : Magnetical Observations in the Ai-etic Seas, by E. 

 K. Kane, M. D., U. S. N., etc. etc., reduced and discussed by C. A. Schott, p. 35 (published in 

 November, 1858). The longitude has been slightly improved. 



^ For latitude and longitude see Astronomical Observations in the Arctic Seas, by E. K. Kane, 

 M. D., U. S. N., etc. etc., reduced and discussed by C. A. Schott, p. 41, Smithsonian Contributions 

 to Knowledge (May, 1860). 



