Calibrating the Hourglass

Returning home from the pond by the evening tram, I found a miniature glass hourglass resting on its side across a stack of lined index cards. A horizontal posture renders such a precise timekeeper thoroughly useless. Stepping onto the smooth card stock, I wrapped both arms around the narrow waist of the clear vessel and hoisted it upward. Bracing my heels against the desk blotter, I tipped it until its flat wooden base struck the desktop with a solid, resonant tap. A slender filament of fine, dark sand immediately surged through the narrow central orifice, gathering into a textbook conical dune below. Naturally, I remained poised nearby with an index finger raised, observing the smooth laminar flow until the final grain settled into place. Orderly temporal progression, duly re-established.