Terrestrial Mag?ieiism with Observation. 



279 



the distribution of the magnetic fluids in the body of the earth, 

 should stimulate every friend of science to contribute his mite 

 towards perfecting the theory. With this view, I have computed 

 from Gauss's theory (see Taylor's Scientific Memoirs, Yol. 11, 

 Art. 5) the three elements for each station of the four tables given 

 in this Journal, Vol. xliii, pp. 99-102, and for comparison have 

 added the data from observation as far as they conld be obtained. 

 The observed variations are taken from the article above quoted, 

 pp. 109-114. Those marked with an (*) were strictly observed, 

 the others were derived from the observations by a method ex- 

 plained in the same article, which also furnishes the reduction to 

 1837. The observations of dip are to be found in the same ar- 

 ticle. For the eastern states the observations are reduced to 

 1837 by assuming the annual motion — 0'-5; for the western 

 states no correction is applied. The observed intensities for the 

 eastern states are from the Transactions of the American Philo- 

 sophical Society ; those for the western states are from Executive 

 Documents, 1839-40, Vol. VI, No. 239. 



Table I. 



