Columbia Encyclopedia

Search results

500 results found

hydrometer

(Encyclopedia)hydrometer hīdrŏmˈətər [key], device used to determine directly the specific gravity of a liquid. It usually consists of a thin glass tube closed at both ends, with one end enlarged into a bulb t...

Charles, Jacques Alexandre César

(Encyclopedia)Charles, Jacques Alexandre César zhäk älĕksäNˈdrə sāzärˈ shärl [key], 1746–1823, French physicist. He confirmed Benjamin Franklin's electrical experiments, became interested in aeronautic...

ice cream

(Encyclopedia)ice cream, sweet frozen dessert, made from milk fat and solids, sugar, flavoring, a stabilizer (usually gelatin), and sometimes eggs, fruits, or nuts. The mix is churned at freezing temperature to att...

isotherm

(Encyclopedia)isotherm, line drawn on a map of a particular region of the earth's surface connecting points of equal temperature; each point reflects one temperature reading or an average of several readings over a...

wind chill

(Encyclopedia)wind chill, the cooling effect of wind and temperature combined, expressed in terms of the effect produced by a lower, windless temperature, also called wind chill factor, wind chill temperature, wind...

thermostat

(Encyclopedia)thermostat, automatic device that regulates temperature in an enclosed area by controlling heating or refrigerating systems. It is commonly connected to one of these systems, turning it on or off in o...

melting point

(Encyclopedia)melting point, temperature at which a substance changes its state from solid to liquid. Under standard atmospheric pressure different pure crystalline solids will each melt at a different specific tem...

degree-day

(Encyclopedia)degree-day, a unit of measure used to estimate the fuel and power requirements in heating and cooling a building; it is equal to a difference of 1 degree between the outdoor daily average temperature ...

grease

(Encyclopedia)grease, mixture of lubricant and thickener. It is used to reduce friction between surfaces from which oils would leak away or cause damage by dripping, or where lubrication must be assured for extende...

hysteresis

(Encyclopedia)hysteresis hĭsˌtərēˈsĭs [key], phenomenon in which the response of a physical system to an external influence depends not only on the present magnitude of that influence but also on the previous...