▁for ▁many ▁sh ar pen ers ▁to ▁have ▁a ▁cas ing ▁around ▁them , ▁which ▁can ▁be ▁removed ▁for ▁empty ing ▁the ▁p enc il ▁sh av ings ▁de br is ▁into ▁a ▁tr ash ▁bin . ▁ ▁History ▁ ▁Before ▁the ▁development ▁of ▁dedicated ▁p enc il ▁sh ar pen ers , ▁a ▁p enc il ▁was ▁sh ar pen ed ▁by ▁wh itt ling ▁it ▁with ▁a ▁kn ife . ▁P enc il ▁sharp ener ▁tools ▁made ▁this ▁task ▁much ▁easier ▁and ▁gave ▁a ▁more ▁uniform ▁result . ▁ ▁The ▁development ▁of ▁p enc il ▁sh ar pen ers ▁began ▁in ▁France . ▁In ▁a ▁French ▁book ▁from ▁ 1 8 2 2 ▁was ▁reported ▁in ▁detail ▁about ▁an ▁in vention ▁of ▁Mr . ▁C . ▁A . ▁B ouch er ▁( Par is ) ▁for ▁construction ▁of ▁a ▁p enc il ▁sharp ener . ▁He ▁was ▁working ▁with ▁p ant ograph s ▁and ▁apparently ▁needed ▁a ▁device ▁to ▁precisely ▁sh ar pen ▁the ▁p enc ils . ▁The ▁device ▁of ▁Mr . ▁B ouch er ▁was ▁techn ically ▁sensible ▁and ▁functional . ▁His ▁idea ▁was ▁also ▁intern ation ally ▁known ▁and ▁recognized , ▁as ▁shown ▁by ▁corresponding ▁reports ▁in ▁German ▁literature ▁at ▁this ▁time . ▁But ▁Mr . ▁B ouch er ▁had ▁not ▁applied ▁a ▁pat ent ▁for ▁his ▁p enc il ▁sharp ener . ▁A ▁commercial ▁use ▁of ▁his ▁invent ions ▁is ▁unlikely . ▁ ▁French ▁math ematic ian ▁Bernard ▁L ass im onne ▁( L im og es