Sur les phénomène des interférences entre deux rayons de lumiere dans le cas de grandes differences de marche. (+) Sur les phénomène des interférences entre deux rayons de lumiere dans le cas de grandes differences de marche, et sur la polarisation ch...

1849. Paris, Victor Masson, Imprimerie de Bachelier, 1849-50. No wrappers. In "Annales de Chimie et de Physique", 3me Series - Tome XXVI a. XXX., Juin 1849 a. Octobre 1850. (The entire issues offered). Titlepages to vol. 26 a. 30. Pp. 129-256 a. pp. 129-256. Fizeau & Foucault's paper: pp. 138-148 a. pp. 146-159, 2 folded engraved plates. Some scattred brownspots. First appearance of thispaper in which the authors demonstrated importent similarities between sound - and lightwaves, and that interference takes place between rays of light of different wavelenghts thus giving considerably evidence for the wave theory of light."By analyzing the white light source into simpler constituents by means of a spectroscope, Fizeau and Foucault were able to observe fringes produced by interfering light rays with a difference of travel equal to more than 7,000 wavelenghts, thus showing hat light waves, like sound waves, remain geometrically constant over a large number of periods. But light waves, because of their transverse vibrations, are more complex than sound waves. Light can assume different forms of planes of vibration as well as different intensities. Using the same spectroscopic apparatus as in the preceeding experiment, Fizeau and Foucault observed the interaction of two rays produced by passing a single polarized ray through a birefringent crystal. In this case, instead of obtaining alternating bands of light and dark, they obtained bands of light periodcally polarized in different planes of vibration."(DSB V, p. 19).