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ction of audible sounds, as articulate speech, etc. It consists of a rotating cylinder or disk covered with some material easily indented, as tinfoil, wax, paraffin, etc., above which is a thin plate carrying a stylus. As the plate vibrates under the influence of a sound, the stylus makes minute indentations or undulat…

rapidly is illuminated by momentary flashes of light passing through slits in a rotating disk. By properly timing the succession of flashes the wheel is made to appear to be motionless, or to rotate more or less slowly in either direction.

A vertical series of alternate disks of two dissimilar metals, as copper and zinc, laid up with disks of cloth or paper moistened with acid water between them, for producing a current of electricity; -- commonly called Volta's pile, voltaic pile, or galvanic pile.

Having the shape of a placenta, or circular thickened disk somewhat thinner about the middle.

A flat piece of metal; especially, a disk of metal ready to be stamped as a coin.

ncients, each having its day. Hutton. -- Planetary nebula, a nebula exhibiting a uniform disk, like that of a planet.

shing snake, a tool used in cleaning lithographic stones. -- Polishing wheel, a wheel or disk coated with, or composed of, abrading material, for polishing a surface.

phonophora found floating in the warmer parts of the ocean. The individuals are round and disk-shaped, with a large zooid in the center of the under side, surrounded by smaller nutritive and reproductive zooids, and by slender dactylozooids near the margin. The disk contains a central float, or pneumatocyst.…

att. xxvii. 7. -- Potter's ore. See Alquifou. -- Potter's wheel, a horizontal revolving disk on which the clay is molded into form with the hands or tools. "My thoughts are whirled like a potter's wheel." Shak. Potter wasp (Zoöl.), a small solitary wasp (Eumenes fraternal) which constructs a globular nest of mud and…

Swimming by the expansion and contraction, or lunglike movement, of the body, or of the disk, as do the medusæ.

performed by puppets moved by wires. -- Puppet valve, a valve in the form of a circular disk, which covers a hole in its seat, and opens by moving bodily away from the seat while remaining parallel with it, -- used in steam engines, pumps, safety valves, etc. Its edge is often beveled, and fits in a conical recess in…

position. Quadrature of the moon (Astron.), the position of the moon when one half of the disk is illuminated. -- Quadrature of an orbit (Astron.), a point in an orbit which is at either extremity of the latus rectum drawn through the empty focus of the orbit.

Having in a capitulum large ray florets which are unlike the disk florets, as in the aster, daisy, etc.

papers. -- Rag wheel. (a) A chain wheel; a sprocket wheel. (b) A polishing wheel made of disks of cloth clamped together on a mandrel. -- Rag wool, wool obtained by tearing woolen rags into fine bits, shoddy.

y, and sunflower. They have an elongated, strap-shaped corolla, while the corollas of the disk flowers are tubular and five-lobed. -- Ray point (Geom.), the common point of a pencil of rays. -- Röntgen ray ( (Phys.), a kind of ray generated in a very highly exhausted vacuum tube by the electrical discharge. It is cap…

A round mass, plate, or disk; especially (Metal.), the crust or scale which forms upon the surface of molten metal in the crucible.

A thick, circular disk of wood, to which the cartridge bag and projectile are attached, in fixed ammunition for cannon; also, a piece of soft metal attached to a projectile to take the groove of the rifling.

A culinary utensil of metal with a plate or disk which is heated, and held over pastry, etc., to brown it.

Fleshy; -- applied to the minute stryctural elements, called sarcous elements, or sarcous disks, of which striated muscular fiber is composed.

nd holding work, in which the jaws are adjusted and tightened simultaneously by turning a disk having in its face a spiral groove which is entered by teeth on the backs of the jaws. -- Scroll saw. See under Saw.