20. The duty to act judicially imposed upon an authority by statute does not necessarily clothe the authority with the judicial power of' the State. Even administrative or executive authorities are often by virtue of their constitution, required to act judicially in dealing with question affecting the rights of citizens. Boards of Revenue, Customs Authorities, Motor Vehicles Authorities, Income-tax and Sales-tax Officers are illustrations prima facie of such administrative authorities, who though under a duty to act judicially, either by the express provisions of the statutes constituting them or by the rules framed thereunder or by the implication either of the statutes or the powers conferred upon them are still not delegates of the judicial power of the State. Their primary function is administrative and not judicial. In deciding whether an authority required to act ,judicially when dealing with matters affecting rights of citizens may be regarded as a tribunal, though not a court, the principal incident is the investiture of the "trappings of a court"-such as authority to determine matters in cases initiated by parties, sitting in public, power to compel attendance of witnesses and to examine them on oath, duty to follow fundamental rules of evidence (though not the strict rules of the Evidence Act),