Hourglass. Grains of sand fall from the upper to the lower glass bulb, measuring a fixed length of time. Hour glasses were first used by the Romans in

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Hourglass. Grains of sand fall from the upper to the lower glass bulb, measuring a fixed length of time. Hour glasses were first used by the Romans in about 1 BC.

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Size: 3801px × 4615px
Photo credit: © SHEILA TERRY/SCIENCE PHOTO LIBRARY / Alamy / Afripics
License: Licensed
Model Released: No

Keywords: 15th, 16th, anatomical, anatomy, arm, artwork, body, century, da, dorsal, drawing, fifteenth, historical, human, illustration, image, imagery, italian, leonardo, monochrome, muscle, muscular, musculature, naked, nude, rear, sixteenth, sketch, system, torso, upper, vinci