The IET Archives has an ongoing programme of recalling artwork and objects from its collections in order to photograph, for reference and conservation purposes, and also to re-examine in order to update catalogue entries where necessary. Some of the items may not have been looked at in any great detail for many years and possibly not since the advent of the internet which makes searching for clues and information about an item that much easier.

As part of this programme we recently uncovered some previously unidentified Michael Faraday material. We had brought back from storage an item which had an early archival reference from the artwork/objects series. The reference was OPC/1/003 and it had the catalogue title, ‘pen and wash magnetic field force maps’. The catalogue entry gave no further description and gave no date for the item.

OPC 1/003 was a framed paper sheet on to which had been stuck 12 individual diagrams. The frame from the 1960s, which was in poor condition and contained rusted metal, has subsequently been removed, and the enclosed sheet has been repackaged. The item with the frame removed is shown below and the diagrams have the appearance of iron filing diagrams that children sometimes produce at school.


The big clue, that this item was related to Michael Faraday, was a faint note in pencil that had been written on the back of the sealed frame in 1960 which said, ‘magnetic field notes made by Faraday – see his monogram on the back – SH Lansley 16/5/60’. The note was very difficult to see and only became visible to the naked eye when the frame was held at a certain angle under the light.

Once the frame, rusted metal and pins had been removed and the diagrams could be examined, it was clear what had been meant by SH Lansley. The individual diagrams were only glued to the backing paper along one edge so the diagrams could be lifted at one side to see what was on the reverse. Many of the diagrams did have a set of initials on the back in the top right hand corner – an example is shown below.


Many of the diagrams also had the outline of magnets inked on to the reverse as shown below;


We have a large number of Faraday letters and notebooks in the IET collections with which we were able to compare the initials, and it did appear to us that the initials were those of Michael Faraday. However, we also sought the views of noted Faraday expert, Frank A J L James, Professor of the History of Science at the Royal Institution, and editor of the six-volume series ‘The correspondence of Michael Faraday’, published by The IET.

Professor James was reasonably sure that the diagrams were iron filing diagrams made by Faraday on waxed paper which he then heated and when cooled permanently captured the patterns. Professor James also referred us to the 1935 print edition of ‘Faraday’s Diary, Volume 6 (11 November 1851 to 5 November 1855)’ where similar diagrams could be found.

Fortunately the complete set of ‘Faraday’s Diary’ is held by the IET Library and volume 6 has extensive references to Faraday’s lines of magnetic force experiments which he undertook in November and December 1851. The preface to volume 6 gives the following information on this subject;

“Folio vol. VI of the manuscript contains a considerable number of the actual specimens prepared by Faraday in 1851 to illustrate the delineation of lines of magnetic force by iron filings. The filings were fixed on cartridge paper by means of gum water, sometimes mixed with a solution of the ‘red ferro prussiate of potasssa’ which was found to leave a blue impression of the pattern after the filings had been removed or worn off”.

Two plates, from volume 6, of these iron filing diagrams are shown below and their similarity to OPC/1/003 is clear.



Given the above we have now amended our catalogue entry to mention that OPC/1/003 is a group of Faraday’s iron filing diagrams from 1851 and to provide some further background!