SAVARY, F. (FELIX). - INSPIRING JOSEPH HENRY'S ELECTRICAL RESEARCHES.

Mémoire sur l'Aimentation. (Lu á l'Academie des Sciences le 31 Juillet 1826). (+) Addition au Mémoire de M. Savary sur l'Aimentation.

Paris, Chez Crochard, 1827. Contemp. hcloth. Gilt lettering to spine. In: "Annales de Chimie et de Physique, Par MM. Gay-Lussac et Arago.", Series 2, Tome 34. 448 pp. a. 1 folded engraved plate. (Entire volume offered). Scattered brownspots.Savary'spaper: pp. 5-57 and pp. 220-221.

First printing of Savary's importent paper, the phenomena investigated here helped Joseph Henry to discover sel-induction, and it was Savary who was the first to describe in this paper his hypothesis of the oscillatory nature of the discharge of a Leyden jar connected to an inductor. In his Mémoire, he documented the experiments which helped lead to his conclusion of the oscillatory discharge of the Leyden jar, which Joseph Henry expanded upon fifteen years later in America while working on his experiments in induction.

"Savary inferred that a charged Leyden jar would discharge in a damped oscillatory manner. This inference was based on observations of magnetization of short thin steel needles. Here needles were placed at varying distances near (and perpendicular) to a 2-meter-long wire loop used to discharge the Leyden jar. Magnetization of the needles would reverse direction (up to three times) as a function of distance from the wire in the loop. (Needles were placed close to the wire starting from a fraction of a mm to about 1 cm away.)
Joseph Henry was stimulated by Savary's observation. Henry repeated Savary's work starting in 1835 and then extended it to magnetizing steel needles in a secondary circuit. Henry published his findings in 1842. Henry placed a steel needle in a spiral in a secondary circuit and removed the secondary circuit to a distance of 30 feet. The magnetizing of a steel needle at this distance is evidence of high frequency transmission and detection. We are working to determine the general range of frequencies of oscillation in Henry's study, but it appears to be near 6 MHz. At 6 MHz the wavelength of the radiation is 50 meters (150 feet), so Henry's observation of magnetization at a distance of 30 feet corresponds to the near field. This remote magnetization is evidence of high-frequency induction rather than radio transmission as is sometimes suggested." (Princeton.edu)

The volume contains other notable papers by Gay-Lussac, Mosander, Boussingault et al. and CLAUDE NAVIER'S importent paper "Sur le Mouvement d'un fluide élastique qui s'écoule hors d'un réservoir ou gazomètre", pp. 400-407.

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