LIEUT.-GENEEAL SABINE ON TEEEESTBJAL MAGNETISM. 



473 



Table XV. 



2. In the ' Terror.' — A spare needle, C, was employed in the ' Terror' as Deflector S. 

 and Deflector N. according as the Deflector was applied to either pole of the Intensity 

 needle ; and two smaller magnets were used conjointly as " N. and S." The equivalent 

 weights were obtained, as shown in the following Table, from the comparison of the 

 angles of deflection with deflectors and weights at Hobarton in April 1841, Sydney in 

 July 1841, Bay of Islands, New Zealand, in August and October 1841 ; Port Louis 

 in the Falkland Islands from April to December 1842 ; St. Martin's Cove (Cape Horn) 

 in October 1842 ; and Simon's Bay (Cape of Good Hope) in April 1843. 



Table XVI. 



From the obsei-vations at Hobarton in April 1841 (regarded as a base station), we have 

 ^=13-540 ; V with Deflector S. 33° 23', and w from Table XIV. 2*614 ; v with Deflector 

 N. 36° 01', and w 2-794 ; and v with Magnets N and S 40° 06', and w 3-060. The angles 

 of deflection in other localities furnish the several values of 1/, and Table XIV. the corre- 

 sponding values of w'. Hence we obtain <p' in other localities, corresponding to 13'640 



at Hobarton as the base station, by (p'= ^^'°^ . w' cosec i/=2'85 w' cosec 1/. 



w 



The degree of accordance between the values of p' as obtained by weights or by de- 



flectors is shown in the following Table. 



