Answer
Precision instruments were significantly enhanced by Charles Édouard Guillaume's discoveries. His development of nickel-steel alloys with near-zero thermal expansion coefficients revolutionized the construction of measuring devices such as clocks, balances, and surveying equipment. These alloys minimized the effects of temperature fluctuations, ensuring greater accuracy and stability in precision measurements. Guillaume's work laid the foundation for advancements in various scientific and industrial fields, where precise measurements are crucial.