ANTIGUO ROTAMETRO MADE IN FRANCE, The Self Registering Rotameter made in France by HC (Henri Chatelain), early to mid twentieth century. It has a scale of 0 to 4 inches x 1/16 inches and a revolution counter counting up to 10 seen through a little aperture near the centre of the face. Dial diameter 30mm. The instructions continue on the underside of the box. MIDE 11,5 CMS.