ESHS/HSS Annual Meeting

Testimony in “Risk”?: Mudge’s Timekeeper and Contested Empiricism in Late Enlightenment Britain

• In Event: Debating Science in the Enlightenment

English Abstract

This study revisits a long-running debate between the Board of Longitude and the watchmaker Thomas Mudge's family in late Enlightenment England. When "uncertainty" at sea demanded reliable instruments, "risk" became a central issue within the empiricism tradition, shaping how measurement, observation, crafts, and credibility could coexist and be contested.

This study traces the debate through archives from Cambridge, the National Maritime Museum, Guildhall Library, and Chatsworth House. In 1774, Thomas Mudge Sr. presented his brass and bimetallic clock for trials at Greenwich, where Nevil Maskelyne kept daily rate sheets and tide notes before judging it "not fit to determine longitude." After his father's death, Thomas Mudge Jr.—of Lincoln's Inn and trained in law—reopened the case, gathering witness statements and pamphlets to challenge the testing procedure. Both sides claimed commitment to empiricism but differed in their interpretation of "risk": the Board managed it through rule, inscribing experience into tables and calculation, while the Mudges treated it as craft judgment, managed through the material operation of metal, heat, and time. Ramsden, Cavendish, and Banks joined the debate, turning a technical evaluation into a wider argument over what counted as reliable experience.

This paper argues that the case shows how testimony became a site of contest, bridging legal and scientific reasoning that has long shaped debates in the historiography of science. In Britain's astronomical and nautical science, the meaning of "risk" remained contested, and empiricism endured in plural forms—negotiated through instruments and observers at sea and on land.

Author

• Haohao ZHANG