to seniority as Chief Petty Officer. (b) Engine-Room Artificers, Ordnance Artificers Electrical Artificers, Shipwright Artificers and Aircraft Artificers of a particular class shall rank and command over all Engine- Room Artificers Ordnance Artificers Electrical Artificers Shipwright Artificers and Aircraft Artificers of a lower class. Within one of these branches sailors of the same class shall rank and command according to their seniority in that class (c) For purposes of departmental work only, in the absence of the departmental officer, the seniormost artificer or mechanician sailor of the department concerned may be directed to take Charge of the department and deputise for the departmental officer.” 9. Therefore, it is apparent that the Chief Artificer’s rank has command over Artificers of classes I to III. Even assuming that Artificers of grades III, II, and I are equivalent to Chief Petty Officers, the Chief Artificers have command over them. 10. At this stage, we may refer to