Mass. Gen. Laws ch. 160, § 237

Any engineer, conductor or other employee on a train discovering a fire burning uncontrolled on lands adjacent to the tracks shall forthwith cause a fire signal to be sounded from the engine, which shall consist of one long and three short whistle blasts repeated several times, and shall notify the next sectionmen whom the train passes, and the next telegraph station, of the existence and location of the fire. This section shall not affect the authority conferred upon the department by section one hundred and thirty-nine.