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The Collaborative International Dictionary

Cinematograph \Cin`e*mat"o*graph\, n. [Gr. ?, ?, motion + -graph.]

  1. an older name for a movie projector, a machine, combining magic lantern and kinetoscope features, for projecting on a screen a series of pictures, moved rapidly (25 to 50 frames per second) and intermittently before an objective lens, and producing by persistence of vision the illusion of continuous motion; a moving-picture projector; also, any of several other machines or devices producing moving pictorial effects. Other older names for the movie projector are animatograph, biograph, bioscope, electrograph, electroscope, kinematograph, kinetoscope, veriscope, vitagraph, vitascope, zo["o]gyroscope, zo["o]praxiscope, etc.

    The cinematograph, invented by Edison in 1894, is the result of the introduction of the flexible film into photography in place of glass.
    --Encyc. Brit.

  2. A camera for taking chronophotographs for exhibition by the instrument described above.


n. (context physics English) a simple device that detects the presence of an electric charge by the mutual repulsion of metal foils or pith balls


n. measuring instrument that detects electric charge; two gold leaves diverge owing to repulsion of charges with like sign


An electroscope is an early scientific instrument that is used to detect the presence and magnitude of electric charge on a body. It was the first electrical measuring instrument. The first electroscope, a pivoted needle called the versorium, was invented by British physician William Gilbert around 1600. The pith-ball electroscope and the gold-leaf electroscope are two classical types of electroscope that are still used in physics education to demonstrate the principles of electrostatics. A type of electroscope is also used in the quartz fiber radiation dosimeter. Electroscopes were used by the Austrian scientist Victor Hess in the discovery of cosmic rays.

Electroscopes detect electric charge by the motion of a test object due to the Coulomb electrostatic force. Since the electric potential or voltage of an object with respect to ground equals its charge divided by its capacitance to ground, an electroscope can be regarded as a crude voltmeter. However, the accumulation of enough charge to detect with an electroscope requires hundreds or thousands of volts, so electroscopes are only used with high-voltage sources such as static electricity and electrostatic machines. Electroscopes generally give only a rough, qualitative indication of the magnitude of the charge. An instrument that measures charge quantitatively is called an electrometer.

Usage examples of "electroscope".

Someone had obviously just finished working at this station it was cluttered with datadisks, an electroscope, and the leftovers of someone's lunch.

Still holding the electroscope, Tash stepped out onto the top floor of the Infirmary.

She had seen that kind of instant replication once before, when she had looked through the electroscope in the medi-chamber.

The electroscope revealed clouds of tiny, wriggling red creatures all around her.

Taking the electroscope from Tash, Hoole confirmed that the virus clouds no longer floated in the room.

Hoole, wearing the electroscope, led the others on a twisting, turning route through the ziggurat's tunnels.

Carrying the box of electroscopes and Monk's portable laboratory, which was contained in metal cases, Doc Savage was almost across the rope before he—the load, rather—was seen from the street below.

In the newspapers also was the matter of the telephone call concerning the electroscopes which Doc Savage had made.

One tabloid had sent a squad of reporters out with an electroscope, and the leaves of the thing flew apart when they neared the first bank, indicating an invisible man.

You know what an electroscope is—two strips of thin tin foil of gold leaf, suspended from a conductor.

When an electroscope is brought into the neighborhood of a piece of radium, the leaves fly apart.

The emanations are not detected by electroscope leaves, but through the reaction of chemicals carrying an almost infinitesimal electrical current.

Later, at the house on this cliff, Monk’s electroscope told me Oxalate Smith was not only here, but had gone in and out of the house a number of times recently.

These same rays can, like X-rays, discharge an electroscope, by making the air which surrounds it a conductor.

However, instead of the usual electroscope, I used a more perfect apparatus.