Invar
INVAR, an alloy of nickel and steel, characterized by an extremely small coefficient of thermal expansion; it is specially useful in the construction of pendulums and of geodetic measuring apparatus, in fact, in all mechanical devices where it is an advantage to avoid temperature compensation. The name was chosen as expressing the invariability of its dimensions with heat. See CLOCK; GEODESY.)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)
