|Recipient Location||Mrs Burnside's, Castle Gate, Nottingham|
|Transcript or Index||[Continuation from previous letter D8760/F/FSJ/1/1/29]|
<across> the connecting wire acquired strong and permanent Magnetism in ten minutes. The same effect is produced by a strong electrical charge passed transversely through the Needle – but, as in most other cases where the two sources of Electrical power are compared, a very strong electric force is necessary to produce the effect of a weak Voltaic one. M. Arago produced the same result by rubbing the Needle backwards and forwards across the wire, and was led to the discovery that the Magnetic power passes in a spiral course round the wire, the North Pole being in one direction when the Needle is above the wire, and in the contrary when below. This curve is that of the Helix or screw <which> may be instanced in the familiar form of the Bellspring; and the Magnetic virtue is much more rapidly acquired by the Needle if it be placed in a tube of this form, & the same then made a part of the Voltaic Circuit, as it is evident that in this case the Needle is still nearly at right angles to the Wire, at every intersection <so that the action upon it is multiplied.> The same effect takes place both in what are called right handed and left handed screws, but opposite Magnetism is produced. Mr Faraday now took up the subject and proved that the identity which had been assumed between electricity and Magnetism does not exist. If the <Voltaic> contact be made on the surface of water, the water rising to the centre of the helix, and the Needle floated on Cork, the Needle will approach the Helix, take its place, and remain fixed at the middle of it – always with the same Pole forward, but it does not attach itself to either end of the Screw. A plate of coiled copper wire suspended in the Voltaic Circuit places itself transversely to the Magnetic Meridian – that is, becomes itself a personification of the Magnetic Equator. A spiral of copper wire, covered with silk, so as to insulate it from electrical action, and suspended in like manner, becomes a Magnet. (You are here invited to refer to the account of Vandel Bos’s Experiments in the Edinburgh Journal of Science, and those of M. de la Rive of Geneva in that of the Royal Institution.) If a pair of Voltaic Plates with a copper spiral fixed horizontally upon them, be suspended in a little cell containing acid, and the whole allowed to float in water, so that it may take what direction it pleases, the voltaic action makes a compass of the above mentioned spiral. The same effect takes place if a vertical ring of copper be made use of instead of the spiral. If a bar Magnet be then presented to it <horizontally> the ring moves towards it, passes over it, and is not contented till it has taken up its place in the central part of the Bar, but whether in the direction of the Magnetic Meridian or Equator, Mr Millington did not say, and I neglected to observe. Mr Faraday hence concluded that the real virtue of a magnet resides near the centre; and pursuing his experiments he found that the Magnet may be made to revolve round the conducting wire, and vice versa, the conducting wire round the Magnetic Centre. Indeed all the phenomena of Magnetism seem to arise only <from> a tendency to produce this revolving motion. A Magnet immersed in Quicksilver and made part of the Voltaic Circuit revolves rapidly on its centre, as may be shewn by the motion of an index above. Mr Barlow’s Experiments now take their turn. If the Magnet be fixed, and in like manner made part of the Circuit it will cause a cylinder of any metal, Brass for instance to revolve round it. If a small bucket of Copper be placed within another of Zinc sufficiently large to contain a little acid between them, and the whole be suspended on a bar magnet, the two vessels immediately begin to revolve in opposite directions. Mr Barlow was curious to observe what would be the effect of a horseshoe Magnet in similar situations as from the two poles being brought so near together he thought it ought to be decidedly different – and indeed found by experiment that the counter influence of the two ends so acted as to produce a rectilinear force. In this manner one wheel was made to turn, or two wheels in separate cisterns of Quicksilver. The experiment had a very pretty effect. Mr Millington now came to his last experiment which he said though insignificant in appearance was not so in its results. It was one made by Mr Faraday, and is I fancy the latest known discovery in this Science. Namely that a delicate wire suspended with its ends in Quicksilver becomes affected by the Magnetic action of the earth. Mr Millington concluded with observing that in all these cases a considerable Voltaic power was necessary, that is, it is necessary that the Metallic plates should be of a large size. The whole of these experiments were performed by him with a single plate of copper between two of Zinc, but they were one foot square, and I should imagine that the acid employed was pretty strong. A much greater number of small plates produces but a feeble effect in comparison, as in fact is generally the case when conducting substances are to be acted upon. It is therefore probable that the Electro-Magnetic phenomena may be the joint effect of Electricity and raised temperature.
In bidding farewell to his audience for the season Mr Millington did not say any thing of our poverty or probable extinction, so I am in hopes that we may be kept alive for another year.
Upper Portland Place. June 21 1823
Gower Street desires remems – as did the Oviatts.
My Dear Sir,
I would fain know honestly whether you found my last “communication” particularly “interesting”, or whether you have really the bad taste to prefer my nonsense to Mr Millington’s Philosophy. I have taken a good deal of pains for you at any rate, and desire you will be duly grateful. Some parts I feel I have given clumsily enough, being out the habit of Lecture writing at present but I do not think I have omitted any fact of importance.
Do not regret that you are called again to an active life! We have surely strong warning that we were not sent here to be idle, and the experience of all ages and climates has shewn how few minds there are strong enough to bear too much solitude. I could say a good deal to you on these matters, but I had rather Time said them for me, for he is the best teacher.
I must not have you angry with my friend either. I agree with Fergus’s Ambassador in Waverley. ”Woe to him who would lose his friend for the stormy cloud of a spring morning”, and I will not allow the remembrance of many years of reciprocal kindness to be cancelled by the spirit of a moment; arising too from illness which I believe had its source in severe anxiety. Poor thing, she received a severe shock yesterday, and I can truly say she should be welcome to use me as she pleased, if any ebullition of expr[essio]n against me could at all alleviate what I know she must be sufferi[ng] now – and so do not be angry with her, for my sake.
I am here, and here you will find me. My sister I have discovered cannot take me in yet without more inconvenience than it is worth while to put her to; and to Mill Hill I cannot return. A degree of cough and oppression and nervous excitement came on me the moment I got there <on Friday week> and increased so much that on Monday Evening I had one of those fits of faintness which I hoped I had taken leave of many weeks ago, and which lasted at least three hours, to Mrs Oviatt’s great alarm. Tuesday was a warm day, and I felt rather better, but Wednesday again brought a bleak Northern wind, and after nursing over a fire all the morning that I might be a less troublesome guest when Mr Oviatt’s brother, who was to dine there, should arrive, I found myself unable to sit at table & was fain to retire to bed. Indeed had I not kept sipping Lemonade and eating Strawberries all the Evening and Night, I believe I should have been in a high fever next morning, simply from the affection of my Chest, for my health was not in the least deranged in any other way. I managed to scribble a note to Dr Thomson begging him to call on me here the next day, but I felt so extremely ill as almost to doubt whether I were capable of making the effort of getting to town to see him. It was made however, & completely proved that I was ill only of a bleak hill & a cold wind, for such was the effect of <a warm day> and removal to a milder air, that by the time he saw me I had only enough of illness remaining from violent coughing and a sleepless night to prove that I had not sent for him without a cause. <You have proof that I was able to attend the Lecture.> I suppose <I had caught> some little cold, which combined with the effect of the air, but it is plain it does not suit me at present. My constitution is certainly changed, and I do not yet understand my new one, and although as he says, I may probably enjoy better health than ever, I feel what he also warned me, that I must be more careful of weather than was formerly necessary – but enough – and indeed you have unhappily had more than enough of my illnesses for a long time past.
I can find no fault with your letters but your abuse of them. It is cruel to make them the bearers of their own condemnation. If they are stupid, pray leave it to me to find that out, which I have not done yet, and can truly say that though I shall rejoice to see you, I shall regret to lose our correspondence, and am not sure whether we have not often been more at ease in our letters than in our meetings. I had a long French epistle from Rouen yesterday, which quizzed me a little. I had <the same subject> from Rome two months ago, and could almost fancy the matter must have been advertized along with your work as a sequel to the “Narrative”! Really we ought to be very vain to find our private concerns matters of so much public interest!! Are you aware of the volume I now send you. I never know the size of this paper till I attempt to fill it, and I believe were it folio, I should still write the same small close hand. Your ever affectionate Eleanor Anne Porden
I am glad you are likely to leave Mrs Burnside better than you at first expected, and hope you are not leaving her too soon – I thought you were to have accompanied your sister to town.
Captain Franklin, R.N.