CUSTOM OF THE CONSTITUTION. 43 office of Governor-General and the Instructions issued to the Governor-General were revised in 1878. By these instru- ments he is authorized to exercise several important execu- tive and prerogative powers vested in Her Majesty, as for instance the summoning, proroguing and dissolving parlia- ment, the pardoning of criminals and the appointment of judges, ministers and other officers. It is not usual on the appointment of the Lieutenant- Governor of a province to issue instructions to him, but such a course has been occasionally adopted. . See Appendix.