Pith Balls

Some articles on pith, ball, pith ball:

Pith-ball Electroscope
... A pith-ball electroscope, invented by British weaver's apprentice John Canton in 1754, consists of a small ball of some lightweight nonconductive substance, originally a spongy ... The ball is suspended by a silk thread from the hook of an insulated stand ... on an object, the object is brought near to the uncharged pith ball ...

Famous quotes containing the words balls and/or pith:

    I count those feathered balls of soot
    The moor-hen guides upon the stream,
    To silence the envy in my thought;
    And turn towards my chamber, caught
    In the cold snows of a dream.
    William Butler Yeats (1865–1939)

    So much of our time is preparation, so much is routine, and so much retrospect, that the pith of each man’s genius contracts itself to a very few hours.
    Ralph Waldo Emerson (1803–1882)