This being an application for a writ of mandate to compel the board of police commissioners to issue permits to certain persons described in the petition to carry weapons, and the statute to which our attention is called making it entirely discretionary with the board of police commissioners, and there being nothing to show that it was the duty of such board of police commissioners to issue such permit, and the writ of mandate being a prerogative writ, which issues only in cases where it is made the duty of any inferior tribunal, board, or person, by reason of their office, to do some act, and there being no such duty imposed upon this board, the judgment is affirmed.