Crystallization to Currentlimit thermostat.

Crystallization of iron. Brittleness caused by improper cooling or hammering.
C-stage resins. (Plast.) Thermoset­ting resins in final stage of reac­tions where they are infusible and insoluble; state of the resin in the final molded article; sometimes called "Resite."
Cuban mahogany. (Wood) A cabinet wood. The hardest and darkest mahogany of commercial importance. Used for furniture manufacture.
Cube. (Geom.) A solid bounded by six equal squares and having all its angles right angles. (Math.) The cube of a number is the product of a number multiplied twice by itself.
Cube root. (Math.) A number which" taken three times as a factor, pro­duces a number called its cube.
Cubical content. The volume; the amount which a vessel will hold. An expression used in reference to buildings as a basis for estimating cost.
Cubic meter. Unit of volume in the metric system. Written: m3. Culm. Dust; slate, and foreign matter removed from coal at the mine.
Culvert. A covered channel for the passage of water, as under a road.
Cumar. A synthetic resin made from coal-tar distillates. It is used as an in­sulator, also in paint and varnish, rubber compounds, and printing ink.
Cumulative. Steady increase in quan­tity or value by repetition or addi­tion.
Cup center. (Mach.) The center which is used in the tailstock of a wood­turning lathe; also called a "dead center. "
Cup chuck. (Woodwkg.) A lathe chuck with a deeply recessed face, used in end-grain turning.
Cup grease. A heavy-bodied, semi­ solid grease used as a lubricant.
Cup joint. (Plumb.) A lead pipe joint in which one end of the pipe is opened enough to receive the tapered end of the adjacent pipe.
Cup leather. (Mech.) A leather pack­ing used for the pistons of hydraulic machines.
Cupola. (Arch.) A dome; generally any small structure above the roof of a building. (Fdry.) A furnace in which cast iron is melted for foundry use.
Cuprite. (Metal.) Cup. Known as red copper ore. Found in Arizona and in a number of South American coun­tries.
Cupronickel. (Metal.) A ductile and malleable alloy of copper and nickel. With varying amounts of nickel, it

Cup shake. (Carp.) A division or opening I?etween two concentric
layers of timber. .
Cup wheel. A grinding wheel shaped like a cup, designed for cutting on its edge.
Curb box. (Plumb.) A device consist­ing usually of a long piece of pipe or tubelike casing, placed ovet a curb cock, through which a key is inserted to permit the turning of the curb cock.
Curb cock. (Plumb.) A valve placed in a service pipe at a point near the curb.
Curdling. (Paint and Lacquer) Incor­porating into lacquer enamel a very fast-drying, weak solvent thinner of very poor quality.
Cure. (Plast.) The changing in the physical form and the properties of a resin by means of chemical reac­tion, following the addition of a catalyst, or heat and pressure, and in some mstances without pressure. A product which is cured is at the end of its cycle of changes.
Cure time. (Plast.) In plastic produc­tion, the interval between the clos­ing of the mold and the instant at which pressure is released. In laminating plastics, the .interval between the addition of the catalyst and hardening.
Curle temperature. The temperature at which a normal magnetic mate­rialloses its magnetic properties.The temperature is usually quite high (1200 C for Chromium Dioxide) and varies with the magnetic material.
Curing. (Plast.) 1)1e change of a binder frl)m the soluble-fusible condition to the substantially insoluble-infusible form by chemical action. The heat. setting of a resinoid. Action is analo­gous to vulcanization of rubber.
Curl. (Furn.) A feather-form marking in the grain of wood.
Curled hair. ( Uphol. ) Is obtained from tails and manes of horses, tails of cattle, and from hogs. It must be put through several processes before it is ready for use. The hair fro'm horses' tails is best for upholstery use.
Curling die. (Mach.) A die used for making a curled edge at the top of any cuplike piece drawn from sheet metal.
Current. (Elec.) The flow of electri­cal energy along a conductor from the higher to the lower of two points
.having different potentials. Current, alternating. The movement of electrons through a conductor,first in one direction and then in the opposite direction.
Current, direct. The movement of electrons through a conductor in one direction only.
Current drain. Current amplification factor.
Current, induced.. A current present in a circuit because of the voltage produced by means of electromag­netic induction.
Currentlimit thermostat. (Elec.) A heat-controlled electrical device used