Diagram of Avery's one-roller tide gauge

This diagram was commissioned by the Science Museum Group in 1927 to depict the design of Avery's one-roller tide gauge.

During the late 19th century, Robert Stanton Avery, an american mathematician and Chief of the Tidal Division of the US Coast Survey, developed a new design of tide gauge.

This redesign had various novel features for its time, including a balance clock instead of a pendulum clock for more accurate measurements, and an improved roller design which made the readings more reliable.