The plaintiff’s testimony established two things only: the mere fact of the accident, and that the ventilating fans were *148not run day and night. The first was not sufficient to warrant a recovery by an employee, and the second did not give rise to an inference of negligence on the part of the defendants which caused the accident. Except in the abandoned rooms where the workmen were forbidden to go, gas was found in the mine at intervals only, when a fall occurred or a clay vein was struck. The failure to run the fans constantly was only one of a number of causes that might account for the presence of gas in the mine on the morning of the accident, and the constant running of them would not have been effective unless the course of the air currents within the mine had been properly directed. This was a matter committed by act of assembly to one over whom the defendants had no control, and for whose neglect they were not answerable. In the absence of affirmative proof of negligence, the nonsuit was properly granted.

The judgment is affirmed.