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sewing machine

(Encyclopedia)sewing machine, device that stitches cloth and other materials. An attempt at mechanical sewing was made in England (1790) with a machine having a forked, automatic needle that made a single-thread ch...

photoelectric cell

(Encyclopedia)CE5 Photoelectric cell: Light causes a photosensitive surface to emit electrons, which flow as current to the positive terminal. A galvanometer measures the current and thus indicates light intensi...

ordeal

(Encyclopedia)ordeal, ancient legal custom whereby an accused person was required to perform a test, the outcome of which decided the person's guilt or innocence. By an ordeal, appeal was made to divine authority t...

mechanics

(Encyclopedia)mechanics, branch of physics concerned with motion and the forces that tend to cause it; it includes study of the mechanical properties of matter, such as density, elasticity, and viscosity. Mechanics...

filibuster

(Encyclopedia)filibuster, term used to designate obstructionist tactics in legislative assemblies. It has particular reference to the U.S. Senate, where the tradition of unlimited debate is very strong. It was not ...

generator

(Encyclopedia)CE5 Generator: The rotation of the conducting coil of wire in a magnetic field causes a current to be induced in the coil. This current is alternating and is conducted from the coil by means of sli...

Navigation Acts

(Encyclopedia)Navigation Acts, in English history, name given to certain parliamentary legislation, more properly called the British Acts of Trade. The acts were an outgrowth of mercantilism, and followed principle...

magic, in religion and superstition

(Encyclopedia)magic, in religion and superstition, the practice of manipulating and controlling the course of nature by preternatural means. Magic is based upon the belief that the universe is populated by unseen f...

mass, in physics

(Encyclopedia)mass, in physics, the quantity of matter in a body regardless of its volume or of any forces acting on it. The term should not be confused with weight, which is the measure of the force of gravity (se...

meson

(Encyclopedia)meson mēˈzŏn [key] [Gr.,=middle (i.e., middleweight)], class of elementary particles whose masses are generally between those of the lepton class of lighter particles and those of the baryon class ...