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Christoph Schissler [attr.], Bacolo o bastone di Giacobbe
Christoph Schissler [attr.], Cross-staff or Jacob’s staff

Late 16th cent.
Wood, gilt brass; length 91,5 cm
Florence, Istituto e Museo di Storia della Scienza, inv. 3167

Variant of the so-called "Jacob’s Staff", a measuring instrument named from its presumed inventor Jacob ben Machir Ibn Tibbon, known as Profatius (13th century). The instrument applies the properties of similar triangles to the measurement of terrestrial and celestial distances.