XXV111 NOTES. 



servations at Hobarton, vol. ii. (1852) p. xlvi. Compare what has been said 

 above in Note 81. " The total force shows less difference at the opposite seasons 

 of the year at the Cape of Good Hope than does the inclination." Magn. Observ. 

 Cape of Good Hope, vol. i. (1851) p. Iv. 



( 122 ) p. 108. See the magnetic portion of my Asie Centrale, t. iii. p. 442. 



( l83 ) p. 108. Sir John Barrow, Arctic Voyages of Discovery, p. 521 and 

 529. 



( 1M ) p. 108. The highest inclination yet observed in Siberia was only 82 

 16'; by Middendorff, on the River Taimyr, in 74 17' N. lat, and 95 42' E. 

 long. (Middend. Sibir. Reise, Th. i. S. 194). 



( 12S ) p. 108. Sir James Ross, Voyage to the Antarctic Regions, vol. i. 

 p. 246. " I had long cherished the ambitious hope to plant the flag of my 

 country on loth the magnetic poles of our globe; but the obstacles which pre- 

 sented themselves being of so insurmountable a character, was some degree of 

 consolation, as it left us no grounds for self-reproach." (p. 247.) 



( 186 ) p. 109. Sabine, Pendulum Experiments, 1825, p. 476. 



( m ) p. 109. Sabine, in the Phil. Trans, for 1840, Pt. I. p. 137, 139 and 

 146. For the movement of the African node, I follow the map appended to 

 that memoir. 



( 128 ) p. 110. I subjoin, as is always my custom, the elements of this not 

 unimportant determination: Micuipampa, a small mountain-town in Peru, at 

 the foot of the Cerro de Gualgayoc; 6 44' 25" S. lat., 80 53' 3" W. long, from 

 Paris; elevation 11, 140 French feet above the Pacific; magnetic inclination 

 0*42 North (centesimal division of the circle). Caxamarca, a town situated 

 on a plain, 8784 French feet above the sea, in 7 8' 38" S. lat, 5 h 23 m 42" 

 W. long, from Paris; inclination 0'15 South. Montan, a hacienda, surrounded 

 by herds of lamas, in the heart of the mountains; 6 33' 9" S. lat., 5 h 26 m 51 s 

 W. long.; elevation 8042 French feet; inclination 0> 70 North. Tomependa, in 

 the province Jaen de Bracamoros, at the mouth of the Chinchipe at its junction 

 with the Amazons; in 5 31' 28" S. lat, 80 57' 30" W. long.; elevation 1242 

 French feet; inclination 3 0- 55 North. Truxillo, a town in Peru, on the sea- 

 coast, in 8 5' 40" S. lat, 81 23' 37" W. long.; inclination 2'15 South. 

 Humboldt, Recueil d'Observ. astron. (Nivellement barome'trique et ge'ode'sique,) 

 vol. i. p. 316, No. 242, 244 254. For the bases of the astronomical deter- 

 minations by star-altitudes and chronometers, see the same work, vol. ii. p. 379 

 391. By a singular accident, the result of my inclination observations in 

 1802 (7 2' S. lat, 81 8' W. long.), notwithstanding the effect of secular 

 change, agrees not badly with Le Monnier's theoretical estimation. He said, 

 " To the north of Lima, the magnetic equator must be found, in 1776, in 7i, or 



