This is an advanced 1885 engineering draftsman protractor tool to design new technology and solve mathematical problems.  Instrument was made by the Kern & Cie, Aarau, Switzerland.  Note adjustable slide center piece.  It is stamped Kern & Cie Aarau Suisse.  Instrument is made of brass with nickel plated and used by professional engineers of the period.  It is in perfect condition.  Also note center piece that appears to be bubble magnifying glass.  Case is leather with purple velvet interior and measures 9” x 5” with instrument slightly smaller.   It will be a highlight to any collection of antique engineering instruments.