Air Core

Air core may refer to:

  • Air core drilling, a form of rotary air drilling
  • Magnetic core

Famous quotes containing the words air and/or core:

    At length, having come up fifty rods off, he uttered one of those prolonged howls, as if calling on the god of loons to aid him, and immediately there came a wind from the east and rippled the surface, and filled the whole air with misty rain, and I was impressed as if it were the prayer of the loon answered, and his god was angry with me; and so I left him disappearing far away on the tumultuous surface.
    Henry David Thoreau (1817–1862)

    The threadbare trees, so poor and thin,
    They are no wealthier than I;
    But with as brave a core within
    They rear their boughs to the October sky.
    Poor knights they are which bravely wait
    The charge of Winter’s cavalry,
    Keeping a simple Roman state,
    Discumbered of their Persian luxury.
    Henry David Thoreau (1817–1862)