Be it enacted by the general assembly of the State of Indiana, That any person who being over sixteen years of age, commits or attempts to commit either the crime of rape, robbery, bank robbery, petit larceny or grand larceny while armed with a pistol, revolver, rifle, shotgun, machine gun or any other firearm or any dangerous or deadly weapon, or while any other person present and aiding or assisting in committing or attempting ot commit either of said crimes is armed with any of said weapons, shall be guilty of a seperate felony in addition to the crimes above named and upon conviction shall be imprisoned for a determinate period of not less than ten years nor more than twenty years . . . .