An Extract from the Journal Books of the Royal Society, concerning Magnets Having More Poles Than Two; by John Eames, F. R. S. with Some Observations by Dr. Desaguliers on the Same Subject

seem'd fill'd near to an exact Level with the Stratum from whence they came. But when the Weather became rainy, the Quantity as well as the Impetus of the Effluvia increased to such a Degree, as to appear in Mornings over the Top of the Well, in the Form of a Mist, and gave great Annoyance to those that came within its Sphere of Action. From hence it is worth observing, that the same Damp, according to the Variation of the Weather, is specifically heavier or lighter than the Air. IX. An Extract from the Journal Books of the Royal Society, concerning Magnets having more Poles than two; by John Eames, F. R. S. with some Observations by Dr. Desaguliers on the same Subject. The sagacious Dr. Halley, in his Account of the Changes of the Variation of the Magnetical Needle; upon the Hypothesis of the Earth's being one great Magnet having four Magnetical Poles, tells us, that he had found two Difficulties not easy to surmount; the one was, that no Magnet he had ever seen or heard of, had more than two opposite Poles, whereas the Earth had visibly four, if not more, &c. I find in looking over the Copy of the Journal-Book of this Honourable Society, Vol. II. an Article in the following Words: D d d July July 20. 1664. "Mr. Ball produced several Load-stones, and among them two Terrella's, whereof one seem'd to have four Poles, with a Circle passing between them, of no Virtue at all. Some of the Company suggested, that it was probable this Stone consisted of two Stones, by Nature cemented together by a Piece that had no Magnetical Quality in it." Query, Whether this Stone can be come at, to examine whether it be a single or a double Stone? An Account of some Magnetical Experiments by J. T. Delaguliers. In the Year 1715, trying some Experiments upon a very large weak Load-stone, I found that it had several Poles: Then I tried several other Load-stones, and often found four Poles in such as had been arm'd when I took off their Armour. In large coarse Stones I found sometimes eight, nine, or ten Poles. This made me believe all Load-stones to have several Poles; but when I tried my Lord Paisley's (since Earl of Abercorn) Load-stones, and other very good ones, I then found that homogeneous Load-stones had but two Poles; those that have more being only an Aggregate of Magnetical and other Matter, which makes an heterogeneous Substance. Such is the Society's great Load-stone; for it has several Poles.