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Object Overview
The early 20th-century hair hygrograph by the renowned manufacturer Jules Richard is a remarkable piece of scientific instrumentation, encapsulating both technical ingenuity and craftsmanship. The instrument’s metal case, covered in its original green varnish, exudes a vintage charm while maintaining the rugged practicality required for accurate atmospheric measurements. The front glass panel provides a clear view of the internal mechanism, allowing the observer to witness the precision in action.
At the heart of the instrument lies a brass drum, driven by an eight-day clock mechanism, which tracks the movement of the inked pen as it registers changes in humidity. The drum is securely mounted on a robust brass base, reinforcing the sturdiness and reliability of the device. On the front of the case, a small brass lever is positioned, allowing the user to easily lift and return the ink pen lever, adding a practical touch to the operational design.
The instrument operates on the hygroscopic properties of horsehair, which is placed outside the case, protected by a metal grill. The horsehair, sensitive to changes in humidity, expands and contracts, which in turn moves the pen on the rotating drum, recording the data with precision.
64574
hygroscopicity
brass, glass, iron
Jules Richard, the son of renowned scientific instrument and clockmaker Felix Richard, continued his father’s legacy after 1876. He later partnered with his younger brother Max, forming the company Richard Frères, which became synonymous with high-quality scientific instruments. Their distinctive monogram "RF" served as the company’s logo, adorning a wide range of instruments, including barometers, anemometers, pyrometers, aneroid barographs, and dynamometers. Although the partnership dissolved in 1891, Jules Richard remained the sole leader of the company until 1921, ensuring the continued production of exceptional instruments under the Richard Frères name.