adjustable slit
Date: 1850-1900
Inventory Number: 1996-1-0717
Classification: Optical Accessory
Dimensions:22.3 × 9.4 × 9.4 cm (8 3/4 × 3 11/16 × 3 11/16 in.)
Description:
A brass stand supports a metallic circle on which was cut an opening. On one side of this opening are two rectangular pieces that moves together by means of a thumb screw. They are designed to adjust the width of the slit. On the other side of the opening is a short and threaded section made in order to attach a tube or other optical device. There are also four holes that were most likely used for the same purpose. The whole upper section of this instrument can pivot.