viii EDITOR'S PREFACE. 



dans le texte. Je reserve tout cela pour des additions a 

 la fin du vol. iv, seconde et derniere section. C'est la que 

 trouveront leur places les changemens que je decouvre 

 dans vos pp. 113-117. Vous sentez, mon cher ami, 

 qu'il sera plus utile de reunir tout ce dont votre tra- 

 duction aura enrichi 1'ouvrage, et de le placer a la fin 

 de 1'ouvrage, en traduisant en allemand les passages 

 entiers quelques longs qu'ils puissent etre." . . . " Je veux 

 que rien ne se perde pour 1'Allemagne de ce qui vient 

 de vous, ayant la prevention de donner dans mon 

 ( Kosmos ' vos travaux dans leur grand ensemble, comme 

 ils ne se trouvent encore nulle part." 



Some passages which occur in the commencement of 

 the first volume of " Kosmos," relating to the physical 

 sciences generally, and to the manner in which, in 

 different stages of their progress, their results are more 

 or less susceptible of being presented under general 

 points of view, appear to me so appropriate to the 

 past and present state of the science of terrestrial 

 magnetism, that in attempting the following brief ex- 

 planation of 'the manner in which I have endeavoured to 

 fulfil the wish conveyed in the preceding extracts, I adopt 

 those expressions in great measure as conveying the views 

 which I entertain, and by which I have been guided. 

 Amongst the many branches into which terrestrial mag- 

 netism divides itself, it is only very recently that some 



