fixed slit with cylindrical lens
Date: 1850-1900
Inventory Number: 2007-1-0535
Classification: Slit
Dimensions:2.6 × 3.8 × 13.1 cm (1 × 1 1/2 × 5 3/16 in.)
Description:
A flat rectangular, blackened brass plate supports a box over a rectangular opening. On top of this box is screwed two brass knife edges at a fixed distance. There is a cylindrical lens attached underneath the opening.