156. Travelling on roof, step or engine of a train. -If any passenger or any other person, after being warned by a railway servant to desist, persists in travelling on the roof, step or footboard of any carriage or on an engine, or in any other part of a train not intended for the use of passengers, he shall be punishable with imprisonment for a term which i-nay extend to three months, or with fine which may extend to five hundred rupees, or with both and may be removed from the railway by any railway servant. | 