ELECTRIC STAMP WATERMARK DETECTOR

THE PHILATECTOR, electric watermark detector.

According to the instruction leaflet, it will effectively reveal watermarks in postage stamps. It does work, although the battery is not included.

It was made by H & A Wallace (Philatelists) Ltd., Old Broad Street, London, EC2.

Size 4.5" x 3" x 1.5". It comes in its original box with slide and supplementary 4 colour filters.