Bulb of Applied Force

In lithic analysis, a subdivision of archaeology, a bulb of applied force (also known as a bulb of percussion or simply bulb of force) is a defining characteristic of a lithic flake. When a flake is detached from its parent core, a portion of the Hertzian cone of force caused by the detachment blow is detached with it, leaving a distinctive bulb on the flake and a corresponding flake scar on the core. Bulbs of applied force may be distinctive, moderate, or diffuse, depending upon the force of the blow used to detach the flake, and upon the type of material used as a fabricator. Generally, the harder the material used as a fabricator, the more distinctive the bulb of applied force.


Famous quotes containing the words bulb, applied and/or force:

    ... until the shopkeeper plants his boot in our eyes,
    and unties our bone and is finished with the case,
    and turns to the next customer, forgetting our face
    or how we knelt at the yellow bulb with sighs
    like moth wings for a short while in a small place.
    Anne Sexton (1928–1974)

    Measured by any standard known to science—by horse-power, calories, volts, mass in any shape,—the tension and vibration and volume and so-called progression of society were full a thousand times greater in 1900 than in 1800;Mthe force had doubled ten times over, and the speed, when measured by electrical standards as in telegraphy, approached infinity, and had annihilated both space and time. No law of material movement applied to it.
    Henry Brooks Adams (1838–1918)

    It is the vice of our public speaking that it has not abandonment. Somewhere, not only every orator but every man should let out all the length of all the reins; should find or make a frank and hearty expression of what force and meaning is in him.
    Ralph Waldo Emerson (1803–1882)