Section 4. Whoever forges, procures to be forged or assists in forging, the stamp of any railroad company or of any railroad ticket agent, or, without lawful authority, stamps or procures to be stamped, or assists in stamping, any railroad ticket or railroad mileage book with such forged stamp, or with a genuine stamp of any railroad company or railroad ticket agent, shall be punished by imprisonment in the state prison for not more than three years or in jail for not more than two years, or by a fine of not more than five hundred dollars.