Design
The experiment consists of two brass bells, each positioned beneath a dry pile (a form of battery), the pair of piles connected in series. A metal sphere approximately 4 mm in diameter is suspended between the piles, and rings the bells by means of electrostatic force. As the clapper touches one bell, it is charged by one pile, and then electrostatically repelled, being attracted to the other bell. On hitting the other bell, the process repeats. The use of electrostatic forces means that while high voltage is required to create motion, only a tiny amount of charge is carried from one bell to the other, which is why the piles have been able to last since the apparatus was set up. Its oscillation frequency is 2 hertz.
Probably the most interesting part of the bell is the pair of dry piles. Nobody is certain what they are composed of, but it is known that they have been coated with molten sulphur to prevent effects from atmospheric moisture and it is thought that they may be Zamboni piles.
At one point this sort of device played an important role in distinguishing between two different theories of electrical action: the theory of contact tension (an obsolete scientific theory based on then-prevailing electrostatic principles) and the theory of chemical action.
The Oxford Electric Bell does not demonstrate perpetual motion. The bell will eventually stop when the dry piles are depleted of charge – that is, if the clapper does not wear out first.
Read more about this topic: Oxford Electric Bell
Famous quotes containing the word design:
“A good scientist is a person with original ideas. A good engineer is a person who makes a design that works with as few original ideas as possible. There are no prima donnas in engineering.”
—Freeman Dyson (b. 1923)
“I begin with a design for a hearse.
For Christ’s sake not black—
nor white either—and not polished!
Let it be weathered—like a farm wagon—”
—William Carlos Williams (1883–1963)
“Delay always breeds danger; and to protract a great design is often to ruin it.”
—Miguel De Cervantes (1547–1616)