COIGNET,MICHIEL CONTRIBUTION TO THE DEVELOPMENT OF THE SECTOR

The contribution of the Antwerp mathematician and instrument maker Mic hiel Coignet to the development of the sector is investigated. It will be shown that he invented a rule, the reigle platte, which he later u sed in conjunction with Mordente's reduction compass, thus in effect p erforming the same operations as with a sector. Later Coignet transfer red the scales to the legs of the compass thereby making his first sec tor, which bore a resemblance to the reduction compass.