Faraday to John Phillips   7 December 1850

53 King’s Road | Brighton | 7 Decr. 1850.

My dear Phillips

It rejoices me to think that you are still looking for Aurora and are thinking about that of which so much is said with assurance & yet so little assuredly know[n]¹. It and the physical cause of the electric condition of the atmosphere are two things which I am persuaded are naturally linked together and yet we may say we know little or nothing of either of them. Now I have fancies but they are as yet not (to me) better they are even worse than other peoples still they return but as you know in London there is no chance of doing any thing with aurora and I am unfortunate in not being able to see even a common chemical experiment with other peoples eyes.

As regards the relation of Electricity & Magnetism in the Aurora there are some observations which if they could be made surely would be of the utmost importance to a true theory. The Aurora affects the Magnet - but how does it affect it? When the needle end goes west is it not rather suddenly? and is that always as the beams mount? Is the first effect on the needle always in the same direction the return effect being merely cessation & is that first effect always in the same direction? that point is I think very important. Or if it be always in the same direction in a station of low latitude is it sometimes the other way in a station of high latitude? or is it at such a station sometimes one way & sometimes the other.

Then in the Southern hemisphere what is the direction of motion & how does it correspond to the movements of the north? Does the S end there agree with the N end in the north or the contrary?

Do your two kinds of Aurora the Arch & beam both affect the needle & both in the same direction?

Oh that we could know a little more about the Aurora & the magnetic needle. Really it is the free needle that we ought to interrogate for the inclination might tell us even more than the declination what is going on if we could obtain it. But it must be a very difficult matter to obtain such indications freely & above all to separate them from other sources of local action some of which though not auroral may be dependant on aurora action[.]

See what outpouring I have given you. If we were together we would have a long talk about the physics of the Aurora borealis[.]

Kindest remembrance to Miss Phillips² from Yours Ever (& wife) | M. Faraday