TEKRESTIUAL MAGNETISM. 71 



1826 1827. Keilhau's observations of the magnetic 

 force at twenty stations (in Finmarken, Spitzbergen, and 

 Bear Island) ; and Keilhau and Boeck's observations in 

 in South Germany and Italy (Schum. Astr. Nachr. No. 

 146.) 



1826 1829. Lutke's Voyage of Circumnavigation. 

 The magnetic part was drawn up with great care in 1834 

 by Lenz. (See Partie nautique du Voyage, 1836.) 



18261830. Captain Philip Parker King's observa- 

 tions on the east and west coasts of South America 

 (Brazil, Monte "Video, Straits of Magellan, Chiloe, and 

 Yalparaiso). 



18271839. Quetelet, Etat du Magnetisme terrestre 

 (Bruxelles) pendant douze annees. Yery exact obser- 

 vations. 



1827. Sabine, Comparison of the relative intensity of 

 the earth's magnetic force in Paris and in London. An 

 analogous comparison of the force in Paris and at Christiania 

 was made by Hansteen, 1825 and 1828 (British Asso- 

 ciation Eeports, 1837, p. 19 23). The numerous results 

 of French, English, and Scandinavian travellers, on the in- 

 tensity of the horizontal force, were first brought into nume- 

 rical connection, so as to afford relative values, by means of 

 these two comparisons, in which intercompared needles were 

 vibrated at the three above-named places. The relative 

 numbers found were : for Paris, 1*348 by me ; for London, 

 1-372 by Sabine; and for Christiania, T423 by Hansteen. 

 All are relative to the intensity of the earth's magnetic 

 force at a point of the " magnetic equator" (or line without 

 inclination), where it intersects the Peruvian Cordillera, 

 between Micuipampa and Caxamarca in S. latitude 7 2', 



