An excavation in Coventry Whitefriars produced a calibrated 16th-century bronze scale on a strip of metal 7 millimetres wide and 31.5 mm long. One end is broken off and the other rounded and pierced with a hole (see Diagram). On the one finished face, it has a scored vertical line and cross calibration lines, numbered 16, 20, 24, 30, 36, then the break. The spaces between the calibration lines from the rounded bottom are: 8 mm, 6.7 mm, 3.5 mm, 3.7 mm and 3.4 mm. The figures are in Arabic, 16th-century style, as often seen on scientific instruments of the period. What might it be?
C. S. Woodfield
Milton Keynes, Buckinghamshire
This puzzle has prompted many answers which are summarised here. Fuller text will be found on our website.
Many correspondents noted that the instrument looks somewhat liked a modern dipstick and that there is a nonlinear relationship between ...
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