Lot Essay
The Guillaume Balance
In 1899, Dr. Charles Edouard Guillaume noted that steel with an addition of 44.4% nickel had a negative square coefficient of thermal expansion. The new alloy, called "Anibal" exhibits unusual properties both in terms of thermal expansion and in changes in elasticity. Anibal, combined with brass in bimetallic laminae, makes expansion close to quadratic. Balances with bimetallic rims made of anibal and brass are usually called Guillaume balances after their inventor.
In 1899, Dr. Charles Edouard Guillaume noted that steel with an addition of 44.4% nickel had a negative square coefficient of thermal expansion. The new alloy, called "Anibal" exhibits unusual properties both in terms of thermal expansion and in changes in elasticity. Anibal, combined with brass in bimetallic laminae, makes expansion close to quadratic. Balances with bimetallic rims made of anibal and brass are usually called Guillaume balances after their inventor.