74 cosmos. 



139 ; (2) Observations made at the Magnetical Observatory at 

 Toronto, 1840, 1841, and 1842 (43° 39' N. lat., and 81° 41' 

 W. long.), vol. i., p. xiv.-xxviii. ; (3) The very variable Direc- 

 tion of Magnetic Declination in one half of the Year at Long- 

 wood House, St. Helena (15° 55' S.'lat, 8° 3' W. long.), 

 Philosophical Transactions for 1847, pt. i., p. 54; (4) Obsei-v- 

 ations made at the Magnetical and Meteorological Observatory 

 at the Cape of Good Hope, 1841-1846 ; (5) Observations made 

 at the Magnetical and Meteorological Observatory at Hobarton 

 (42° 52' S. lat., 145° 7' E. long.), in Van Diemerfs Land 

 and the Antarctic Expedition, vol. i. and ii. (1841-1848); On 

 the Separation of the Eastern and Western Disturbances, see 

 vol. ii., p. ix.-xxxvi. ; (6) Magnetic Phenomena within the 

 Antarctic Polar Circle, in Kergueleris and Van Diemeris Land 

 (Phil. Transact, for 1843, pt. ii., p. 145-231); (7) On the 

 Isoclinal and Isodynamic Lines in the Atlantic Ocean, their Con- 

 dition in 1837 (Phil. Transact, for 1840, pt. i., p. 129-155); 

 (8) Basis of a chart of the Atlantic Ocean, which exhibits 

 the lines of magnetic variation between 60° N. lat. and 60° 

 S. lat. for the year 1840 (Phil. Transact, for 1849, pt. ii., p. 

 173-233); (9) Methods of determining the absolute Values, 

 secular Change, and annual Variation of the Magnetic Force 

 (Phil Transact, for 1850, pt. i., p. 201-219); Coincidence 

 of the epochs of the greatest vicinity of the sun with the 

 greatest intensity of the force in both hemispheres, and of 

 the increase of inclination, p. 216; (10) On the Amount of 

 Magnetic Intensity in the most Northern parts of the Neio Con- 

 tinent, and upon the Point of greatest Magnetic Force found by 

 Captain Lefroy in 52° 19 / lat. (Phil. Transact, for 1846, pt. 

 iii., p. 237-336); (11) The periodic Alterations of the three 

 Elements of terrestrial Magnetism, Variation, Inclination, and 

 Intensity at Toronto and Hobarton, and on the Connection of the 

 decennial Period of Magnetic Alterations with the decennial 

 Period of the frequency of Solar Spots, discovered by Schicabe 

 at Dessau (Phil. Transact, for 1852, pt. i., p. 121-124). The 

 observations of variation for 1846 and 1851 are to be con- 

 sidered as a continuation of those indicated in ISo. 1, as be- 

 longing to the years 1840-1845. 



1839. Representation of magnetic isoclinal and isodynam- 

 ic lines, from observations of Humphrey Lloyd, John Phil-, 

 lips, Robert "Were Fox, James Ross, and Edward Sabine. 

 As early as 1833 it was determined, at the meeting of the 

 British Association in Cambridge, that the magnetic inclin- 

 ation and intensity should be determined at several parts of 



