Description

A very rare example of the early mathematical and innovative sector developped by John Worgan in the late 17th century and described and illustrated by him in his publication appearead in 1697 under the title : “A Short Treatise of the Description of the Sector”.

In this short booklet of 35 pages and three plates of which one is illustrating the sector, Worgan “shown the admendments that have been lately mad ein disposign the Lines hereon plac’d, and the advantages accrewing thereby”.

The Worgan sector is not a copy of previous instrument but a innovative instrument.

The present brass example is absolutly similar to the illustration in the 1697 : the type of engraving, the line and their position, the simple joint, etc.

The sector is simply signed “I. Worgan Fecit”.

On one side is engraved the lines of “Tangents”, “Chords” and “tangents”

On the other side, the lines present are “Sines”, “Lines” [ie Equal parts], “secants” and “Polygones”.

On the edge of the compass, the sector is divided in 12 inches forming a English feet.

John Worgan, a well-respected instrument maker of London’s Fleet Street from 1686 to 1714  was part of a group of skilled instrument makers. He apprenticed to the famous mathematical instrument maker, Walter Hayes (recorded working in London from 1648 to 1687) who was succeeded by another of his apprentices, Edmund Culpeper, maker of the famous Culpeper type of microscope.

A English instrument of great rarity by a famous London maker from the 17th century.

The condition is excellent with a nice and old patine.

The instrument measures 16,2cm lenght closed.