A civil engineer carried out public inquiries from time to time for the Secretary of State for the Environment, and received a per diem fee for doing so. It was held that holding an inquiry did not make him the holder of an office, and his fees accordingly were taxable as professional income rather than as income from an office or employment. The word "office" "must involve a degree of continuance (not necessarily continuity) and of independent existence; it must connote a post to which a person can be appointed, which he can vacate and to which a successor can be appointed," whereas the positions of the taxpayer were "'tailor-made'" to his talents.