Faraday to Johann Rudolf Wolf   27 August 1852

I am very greatly obliged and delighted by your kindness in speaking to me¹ of your most remarkable enquiry, regarding the relation existing between the condition of the Sun and the condition of the Earths Magnetism. The discovery of periods and the observation of their accordance in different parts of the great system, of which we make a portion, seem to be one of the most promising methods of touching the great subject of terrestrial magnetism. The power is wonderful;- and the whole problem set before philosophers, very complicated; - whilst at the same time our opportuniti[e]s of access to the power are very few and imperfect:- for, what is going on in the bowels of the earth who can tell. But we have first to discriminate amongst the great things which can or do, affect the power; and knowing, first of all that much concerning its seet [sic] must be within the earth, it is then a great advance to know that the Sun has also much to do with it;- and again (as I beli[e]ve fully) that the atmosphere by its oxygen has a great deal to do with it also. These division though at first imperfect, are the beginning of the analysis of the power; by which kind of analysis we can alone hope ultimat[e]ly to understand its nature and natural arrangement and variations.