VALLEMONT (L. de). DESCRIPTION OF THE MAGNET WHICH FORMED AT THE POINT OF THE NEW BELL TOWER OF N. DAME DE CHARTRES. Paris, d'Houry, 1692. In-12 of [12]-215-1bl. pages, brown calf, spine ribbed and decorated (contemporary binding). First edition of this important treatise on magnets and magnetic theory by the Jesuit and theologian Le Lorrain de Vallemont. He describes a violent storm in October 1690, destroying the bell tower of Notre-Dame de Chartres, during which the phenomenon of magnetism manifested itself clearly through a piece of iron belonging to the church tower. A figure in the text. One cap damaged.