and of their divergence and convergence, guides Faraday without
perplexity through all the intricacies of the question. After the
completion of those researches, and in a paper forwarded to the
Royal Society on October 22, 1851, he devotes himself to the formal
development and illustration of his favourite idea. The paper bears
the title, 'On lines of magnetic force, their definite character,
and their distribution within a magnet and through space.'
A deep reflectiveness is the characteristic of this memoir.
In his experiments, which are perfectly beautiful and profoundly
suggestive, he takes but a secondary delight. His object is to
illustrate the utility of his conception of lines of force.
'The study of these lines,' he says, 'has at different times been
greatly influential in leading me to various results which I think
prove their utility as well as fertility.'

Faraday for a long period used the lines of force merely as
'a representative idea.' He seemed for a time averse to going further
in expression than the lines themselves, however much further he may
have gone in idea. That he believed them to exist at all times
round a magnet, and irrespective of the existence of magnetic
matter, such as iron filings, external to the magnet, is certain.
No doubt the space round every magnet presented itself to his
imagination as traversed by loops of magnetic power; but he was
chary in speaking of the physical substratum of those loops. Indeed
it may be doubted whether the physical theory of lines of force
presented itself with any distinctness to his own mind.
The possible complicity of the luminiferous ether in magnetic phenomena
was certainly in his thoughts. 'How the magnetic force,' he writes,
'is transferred through bodies or through space we know not; whether
the result is merely action at a distance, as in the case of gravity;