Ever sinced the creation of the first graphite pencil in the late sixteenth century people have used knives to whittle their pencils to a point.  By the 1800's, inventors began designing special purpose pencil sharpening devices.  The range of solutions to the challenge of sharpening pencils is extraordinary.  Together the pencil sharpeners in this collection demonstrate the immense creativity of the engineers of the late 1800's and early 1900's.  By 1915, a pencil sharpener with a mechanically superior design--one with twin planetary cylindrical cutters--was offered for sale for the price of $1.  Shortly thereafter, pencil sharpeners with this design were the only mechanical sharpeners sold.  Even to this day, mechanical pencil sharpeners remain substantially unchanged