Imprisonment in default of fine limited by magistrate's sentencing power and proportionality to substantive imprisonment. A Magistrate may impose imprisonment in default of payment of fine as authorised by law, but the term must not exceed the Magistrate's statutory sentencing power. If imprisonment is part of the substantive sentence, the default-imprisonment component is limited to one-quarter of the maximum term the Magistrate could otherwise impose for the offence. Imprisonment under this provision may be ordered in addition to a substantive term up to the Magistrate's maximum statutory term.