In the north-west corner of the top floor of the museum sits the imposing natural magnet given to the Ashmolean Museum by the Countess of Westmorland in 1756.

The stone itself, which according to the original accession record is 48 inches in circumference, is displayed in a mahogany case and mount, elegantly highlighted with a gilt ducal coronet surrounding the magnet, donated at the same time as the loadstone by the Earl of Westmorland. The stone as displayed is capable of supporting a weight of 160 lbs.

While information about the Countess and the history of the object both before and after it was acquired by the museum remains elusive, the loadstone points to interesting issues in the history of women in eighteenth-century science.

Mary Cavendish (1698-1778) was the daughter of Lord Henry Cavendish (d.1710), the second son of William Cavendish, first Duke of Devonshire (1640-1707). The family was prolific and included fellows of the Royal Society, a daughter of Elihu Yale, and an uncle of Horace Walpole.

Mary Cavendish is known to have been friends with Mary Delany, who herself had a considerable collection of shells and made masterful decoupage 'pictures' of flowers. Both were amongst the crowd who went to Westminster in March 1738/9 to protest against the treatment of British merchants by the Spanish government, which resulted in the declaration of war in 1739.

In this same circle was Margaret Harley Cavendish Bentinck, the Duchess of Portland, whose magnificent collection of shells was of significant scholarly interest. She, in turn, was the granddaughter of Margaret Cavendish, the Duchess of Newcastle (1624?-1674), who published her views on natural history at her own expense, an almost unique feat for a woman with scientific interests at that time.

The Countess of Westmorland clearly came from an environment where it was permissible for women to take some interest in science but nothing survives demonstrating her own involvement. It is not clear where she acquired the loadstone or when. The inventory of her father's house does not record it, nor does Horace Walpole mention having seen it when he visited her home, Mereworth in Kent, in August 1752, although he does discuss the seat in some architectural detail and notes some of the contents. Walpole evidently held the Countess herself in some esteem, describing her at the time of the coronation of George III as 'still handsome' and with great dignity.

Despite this vagueness about where and why the Countess acquired the loadstone, there is no doubt that it was she who gave it to the Ashmolean. The entry in the celebratory Donor's Book records her gift of the stone and some books, as well as the Earl's contribution of the case.

The Countess's responsibility for the gift became an issue again the year after she donated it when William Huddesford, the Keeper of the Ashmolean, desired to have an engraving made of the loadstone with a note about its provenance. When he wrote to the Earl on the topic, the reply was unenthusiastic. While there was no objection to the production of the print, the Countess desired that 'in the descriptive part you intend, her name may not be inserted.'

Her objections were never clearly explained. While 'sensible of [Huddesford's] politeness' in regard to making the print, the Countess 'has her reasons' for withholding her name from print, it was reported. In the event, however, she overcame 'her Scruples at the thought of seeing her name engraved' and in the end submitted to Huddesford's desire to publicise how the object came into the museum as there was 'no reasoning against it'.

While there is no way of knowing why the Countess was reluctant to see her name associated publicly with the gift, several possibilities present themselves. Since the manner in which she came into possession of the object remains obscure, it is possible that she felt little responsibility for being in a position to give it to the museum. This might be particularly true if she had little interest in natural philosophy, though if this were the case she might have given the object anonymously.

A second possibility is that though privately interested in natural philosophy, she felt it inappropriate for a woman to advertise publicly such an involvement. Women were not permitted to be fellows of the Royal Society and were almost never welcome at its meetings. They virtually never published their own ideas on such topics and not until the nineteenth century did it become common for them to write popularising tracts on natural history, especially for children. There was doubtless consider able pressure at the time for the Countess to keep her interest to herself.

A final cause for circumspection may relate to the choice of the Ashmolean as a receiver of the loadstone. Mary Cavendish married John Fane, who in 1736 succeeded to the Earldom of Westmorland. Amongst the many public offices Fane held during his career, he emerged victorious from a hotly contested election for Chancellor of the University. The publication of Mary's name, and hence his, in connection with the gift to the museum might have been considered inappropriate or inadvisable given Fane's political position in the University.

Whatever the misgivings, the engraving was published and reprinted in the 1836 catalogue of the Ashmolean, where the magnet is listed under the heading of 'Miscellaneous Curiosities'. Only two other objects were classed with it: a gold-headed cane embossed with the story of the Good Samaritan and an image of Faraday.

Perhaps already by this time the presence of the magnet within the museum's collection was being questioned. Over the next hundred years, it passed from the Ashmolean to the University Museum, spending a short period in the Clarendon Building between times.

After the Museum of the History of Science was established, a formal request was sent in 1941 to the University Museum for the return of the Countess's magnet. Amongst the several arguments promulgated in favour of such an action was that the magnet formed part of the original Ashmolean collection and hence had a long association with the Old Ashmolean building.

It was also argued that the decoration of the loadstone almost entirely obscured any mineralogical interest there might be in it and that, moreover, along with its case, the loadstone was a superb example of the combination of artistic and scientific qualities typical of the eighteenth century. The museum also already had several smaller decorated examples of loadstones. Finally, it was said, the stone-vaulted basement of the museum would be safer in the case of aerial bombardment than the University Museum would be.

In the event, the University Museum agreed to the transfer, noting that they no longer really considered it part of the mineralogical collection. The Countess's loadstone effectively changed its identity from being a geological specimen to one of historical interest.

Patricia Kell