FOUR-SUNDIAL COMPENDIUM, English, c. second half 17th century, signed “Phil. Edwards.” Constructed of fine boxwood, this unusual diptych compendium measures 4″ x 4-1/4″ x 1″ (10 x 11 x 2.5 cm) closed. Surface Ia is divided, every quarter hour, with a twice-12 hour scale full circle, and would work in summer, when the sun is above the plane of the equator, with a central straight pin as gnomon. Surface Ib is again divided, half-circle, from 6am to 6pm, functioning
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