English 19th century 6″ ivory sector unmarked
Typical nineteenth century sector, having scales for inches, decimal feet, lines of sines, tangents, equal parts, chords, numbers (log scales for multiplication), polygons, secants.
Sectors were frequently included in sets of drawing instruments in the eighteenth and nineteenth centuries until made obsolete by the slide rule.
In good sound condition, slight hairlines at two hinge rivets, no damage or repair and little wear.
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As a fine art sculpture graduate I have applied my appreciation and understanding of form and function to my lifelong professional career in the antiques trade. Over forty years dealing in what I considered worthy, within the fields of decorative arts and sciences, I have always purchased over a wide spectrum and look forward to offering an exciting variety of stimulating pieces.