A major cause of error in balance wheel timepieces, caused by changes in elasticity of the balance spring from temperature changes, was solved by the bimetallic temperature compensated balance wheel invented in 1765 by Pierre Le Roy and improved by Thomas Earnshaw.
A major cause of error in balance wheel timepieces was solved by the bimetallic temperature. This bimetallic temperature was compensated balance wheel invented in 1765 by Pierre Le Roy and improved by Thomas Earnshaw. A major cause of error in balance wheel timepieces was caused by changes in elasticity of the balance spring from temperature changes.