9No penalty to be exacted in case of unavoidable accident.
No penalty shall be exacted in any case when it shall appear to the satisfaction of the justice or justices that the person failing to comply with the provisions of this Act relating to the transmitting of returns or notices under the provisions herein-before contained has so failed by unavoidable accident, or by circumstances over which he had no control, and having used every reasonable endeavour towards compliance with such provisions.