Vintage Dr William Thomson Lantern for Railroad Marine Service Color Blind Detector “RARE”

 Dr. WILLIAM THOMSON: Lantern for Detecting Color-Blindness.

MODEL: #3 

DATE: 1911

CONDITION: PRISTINE 

All Original “(Added shrink tubing & tape to avoid cord damage)”
A lamp or lantern then as an adjunct to the " color wool stick," to be used, if desired, under the supervision of the division superintendent by intelligent laymen. With this addition to the Pennsylvania Railroad system it seems to me more complete, and sufficient to eliminate from any road all color-blind employees and to furnish an insuperable barrier to their admission to the service.

It consists of an asbestos chimney, which can be placed on an electric lamp, or spring candlestick.

Two discs four inches in diameter are so placed upon the chimney as to permit of their being superimposed partly. The lower disc contains ten glasses in apertures IO mm. in diameter, having the white, red, green, and blue colors in general use on railroads