Autograph letter signed to Samuel H. Christie

Paris, 1824. Ampère, André Marie (1775-1836). Autograph letter signed to [Samuel Hunter] Christie (1784-1865). Paris, 14 July 1824. 1 page. 225 x 175 mm. Light marginal staining, lacuna from ink oxidation affecting one word. From Ampère, founder of the science of electrodynamics, to British mathematician and physicist Samuel Hunter Christie, who performed important research on terrestrial and other forms of magnetism: "Depuis que vous m'avez fait l'honneur de m'envoyer votre excellent mémoire sur le sujet de physique sur lequel nous travaillons particulièrement tous deux, je désirais vivement trouver une occasion pour vous envoyer un des 3 ou 4 exemplaires (truncated) qui me reste de mon ouvrage sur ce sujet dont l'édition est épuisée. . . .Je joins à mon recueil une petite brochure qui en est extraite et qui est l'exposé rapide de tous les faits découverts relativement à l'électricité dynamique." [Ever since you did me the honor of sending me your excellent memoir on the subject of physics on which we are both particularly working, I have wanted very much to find an occasion to send you one of my 3 or 4 remaining copies of my work on this subject, which is out of print. . . . I add to my work a small pamphlet extracted from it, which is a brief summary of all the discoveries relating to electrodynamics.] The "ouvrage" Ampère referred to here was his Recueil d'observations électro-dynamiques (1823), representing "the most complete single summary of his accomplishments to that date" (Hofmann, p. 321); the work included observations on terrestrial magnetism. The "petite brochure" was Ampère's Précis de la théorie des phénomènes électro-dynamiques pour servir de supplément au "Recueil d'observations électro-dynamiques" (1824). Ampère, whose scientific creativity far exceeded his powers of organization, was in the habit of issuing numerous revisions, additions and explanations to his previously published works; the Précis is an example of this practice. Ampère sent these two publications to Christie via his friend Baron Jean-Frédéric Maurice (1775-1851), a Swiss-born mathematician and astronomer. Samuel Hunter Christie, Ampère's correspondent, is best known for inventing a forerunner of the "Wheatstone bridge" method for comparing the resistances of wires of different thicknesses, published in the Philosophical Transactions in 1833. At the time of Ampère's letter Christie had published two works, Observations on Magnetic Attractions (1821) and On the Diurnal Deviations of the Horizontal Needle when under the Influence of Magnets (1823). We do not know which one of these he presented to Ampère. Hofmann, André-Marie Ampère (1995). . (Inventory #: 40488)