GOOD EARLY EXAMPLE OF A 18TH CENTURY BONE OPTICAL COMPENDIUM COMPRISING OF A SIMPLE MICROSCOPE/FLEAGLASS, TELESCOPE & A POLY-PRISM, OVERALL LENGTH 5" INCHES. THESE LITTLE INSTRUMENTS WERE OFTEN MADE BY CULPEPER OR WILLDAY. PLEASE NOTE THIS HAS BEEN PROFESSIONALLY IDENTIFIED AS BONE. PLEASE SEE THE BLACK FLECKING AND SHAKES ALL OVER, THESE ITEMS WERE MADE OF DIFFERENT MATERIALS, BONE WAS OFTEN FAVOURED USING THE NATUAL HOLLOW TO ASSIST CONSTRUCTION. PLEASE SEE MY OTHER EXAMPLE ON MY PAGE FIVE ON FLEAGLASS.