FIRST EDITION IN ENGLISH, in original wrappers, of what is generally recognized as the earliest paper on hydrodynamic stability. Preceded by the printing in German of the same year.
"In 1868 Helmholtz published a paper on what happens along the contact surface of two infinitely extended fluids if the one moves relative to the other. In that publication, 'Uber dickontinuirliche Flussigkeits-Bewegungen,' [On discontinuous fluid motions], he pointed out that if a water jet issues from a sharp-edged orifice into a tank filled with water, a discontinuity in the velocity distribution is observed at the edge of the orifice. In is view, in a non-viscous fluid a whole surface of discontinuity separating the jet from the surrounding quiescent water can be assumed. Even though Helmholtz had doubts as to the stability of such a surface of discontinuity, he suggested that such a region of irrotational flow bordered by surfaces across which the velocity, but not the pressure, suffers a discontinuous change, should be investigated. The challenge was met by Lord Kelvin... [It] had a pivotal influence... Helmholtz-Kelvin instability, as it came to be known, became an active topic for research among theoretical fluid dynamicists over the following century" (Pasipoularides, Herat's Vortex: Intracardiac Blood Flow Phenomena).
IN: The London, Edinburgh, and Dublin Philosophical Magazine, Fourth Series, No. 244, November 1868, pp. 337-348. Octavo, original printed wrappers. Wrappers with light soiling and mild wear to spine and edges. Rare in original wrappers.
Price: $850 .