Lamp & Scale Arrangement with Transformer

It is based on 'GRIFFEN' Pattern which is highly suitable for reflecting 'BESTO' Ballistic Galvanometers. It consists of a heavy steel cabinet made from S. W.G. 20 sheet of size 6" x4" x3½" with front printed panel. In this steel cabinet, a step down transformer of 6 volts, 3.5 Amps is enclosed, which is suitable for the lamp house.
The lamp house is made from Aluminum-Silver Alloys, machined and finished in a pleasing Duco paint. It is fitted with a special 6 Volts 20 Watt bulb which is connected to the transformer with special banana plug.
The lamp house is fitted with a rack and pinion arrangement for focusing. A double convex lens made from imported glass of 18mm diameter of 4" focal length is used in it for better results.
The lamp house can slide up and down along the vertical rod fixed on a steel cabinet. The inclination of the lamp can be adjusted in vertical plane. 
Bright light through the convex lens falls on the concave mirror of the 'BESTO' Ballistic Galvanometer and forms a bright spot on the translucent Perspex scale fitted in a special bracket above the lamp house which is divided into 25-0-25 cm. and 0 to 50cm.