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xv, [1], 34 pp. With six fold out plates at rear. (4to) later quarter morocco and cloth, marbled endpapers. First Edition. 

A presentation copy, with "From the author to General Melville" inscribed on a blank preliminary page. From the library of Harrison D. Horblit, with his book label on the front free endpaper. John Lorimer was a surgeon, mathematician, politician and cartographer in the 18th century, with a particular interest in terrestrial magnetism. In this volume he describes his "Universal Magnetic needle" the prototype of which was constructed in 1864 by Jeremiah Sisson. The instrument measured both the horizontal direction and dip of the earth's magnetic field. The needle never was popular probably because it was too elaborate. The original was donated to Lorimer's alma mater, the University of Aberdeen.