It shall be unlawful for any person, firm, or corporation to employ another, who is under the age of twenty-one (21) years, to operate or drive a taxicab or bus for hire, or otherwise, in cities of the first class in this state. Any person found guilty of a violation of this subchapter shall be guilty of a misdemeanor and shall be fined not less than twenty-five dollars ($25.00) nor more than fifty dollars ($50.00) for each offense.