The perimeter is an instrument for the accurate charting of the field of vision. A vertical stand on witch a METALLIC ARC is pivoted.

 

it also bears a circular black disc to read the meridian in witch the arc in the shape of a semicircle with a radius of 330 mm. It’s rotating in any direction and fix at any position with a tightening screw.

 

Priestly Smith Table Model. Used to measure the peripheral field of vision. The apparatus comprises of a calibrated are contains five colors and five apertures of different diameter calibrated scale. Adjustable chin rest.

 

All fitted over a sturdy base with a receptacle for keeping charts. For tabletop use, with 100 charts.