THE MOST IMPORTANT WORK ON MAGNETISM SINCE GILBERT’S DE MAGNETE (1600) AND LIKE THAT BOOK A LANDMARK OF EXPERIMENTAL SCIENCE
A short treatise of magneticall bodies and motions
London: printed by Nicholas Okes, 1613
4to: A4 (A2+a4) B–V4 X4 (+/–X3) (blanks A1 and X4), 88 leaves, pp.  157  (first and last 2 pages blank). Woodcut initials, printer's woodcut device dated 1610 on colophon on X3. Engraved titlepage on A2 signed ‘R: Elstrak sculpsit’ (Johnson p. 15), engraved portrait on a4v, 20 three-quarter page engravings in the text numbered Tab. I–XX, that on p. 137 with a movable quadrant attached by a thread, 1 unnumbered half-page engraving on p. 143 and one woodcut on p. 152.
Condition: 191 x 145mm. Purple mildew stains throughout but the paper apparently resized and crisp; minor repairs to first few leaves and initial and terminal blanks and some other leaves chipped in the margins, movable piece on p. 137 pasted down.
Binding: Newly stab-sewn and recased in what could be the original vellum wrapper made from a contemporary indenture.
Provenance: Walter Pagel (1896–1983); B. E. J. Pagel (1930–2007). No marks of Pagel or other provenance.
First edition, second issue with X3 cancelled and errata printed on the replacement leaf.
Bibliography: STC 21045.5; ESTC S123258; Adams & Waters, 2976; Wheeler Gift 86.
A landmark in the history of experimental science in England, this was the most important work on magnetism after Gilbert's De magnete (1600).
‘Dr Ridley, following up Dr Gilbert's work, here presented directions for a series of experiments on the lodestone, magnet, and terella which could be carried out by anyone interested in the subject. He added engravings and descriptions of his improvised instruments for determining the variation, and for making use of the inclinatory needle for finding position at sea. This was in accordance with the method published jointly by Edward Wright, Thomas Blundeville, and Henry Briggs.’ (Taylor, Works, 126).
Like Gilbert, Ridley was a prominent fellow of the College of Physicians and the two were close friends. But Ridley was dismissive of another contemporary experimenter who was in contact with Gilbert, William Barlow. Barlow accused Ridley of plagiarism, saying that Gilbert had shown Ridley the manuscript of his Magneticall advertisements, not published until 1616. Ridley replied to this accusation in his only other published work, Magnetical animadversions (1617). He there ridiculed Barlow's anti-Copernican arguments, pointing out the recent discovery of Jupiter's satellites by the telescope. It is therefore interesting that Jupiter's satellites are shown on the engraved titlepage of the present work, published 4 years earlier.
In his address to the reader, Ridley discusses the images of the planets on the titlepage, so presumably he had himself directed the engraver, Renald Elstrack (1570–1625 or later). The lower half of the engraving seems to show the entrance to a classical building, flanked by paired Doric colums, but above, the building disolves into a display of scientific instruments, the planets, and an elephant with a howdah. Elstrack is regarded as the foremost English engraver of his time, particularly as a portrait engraver (ODNB). Johnson identified 24 titlepages engraved by him between 1610 and 1624. It is obviously tempting to attribute the portrait of Ridley to Elstrack, but Hind dismisses this on the grounds that the engraving is not up to Elstrack's standard. However the lettering on the titlepage and under the portrait does seem to have been done by the same hand, but this could have been added by a specialist letter engraver. The plates of instruments are less finely engraved, and apart from their interest for the history of scientific instruments, they include one with two circular polar maps, one showing Terra Australis, the other New England and Virginia. The plate on p. 137 has an attached volvelle in the form of a movable quadrant.
Although the mildew staining is unsightly, this is a good complete copy. This kind of staining is impossible to remove without bleaching, but the paper has been stabilised and repaired. The book was apparently originally stab sewn through three holes in the vellum wrapper. During restoration, which appears to have been done fairly recently, the text block has been newly stab sewn through five holes and the wrapper glued to the spine. The mildew staining is quite heavy on the vellum wrapper and the pattern matches the text block. The wrapper is made from an indenture with a calligraphic heading concerning the lease of some land to one James Waterman but the date is missing. It could well have formed the book's first covering, but it is now hard to be sure. Survivals of books stab sewn in simple vellum wrappers like this are rare.
Literature: For Renald Elstrack and the attribution of the engraved portrait see Arthur Mayger Hind, Engraving in England in the Sixteenth and Seventeenth Centuries (1952) II. 379.40.