, (c), (e) and (g) define "Contract Labour", "Contractor", "Establishment" and "Principal Employer" in the following terms: "(b) a workman shall be deemed to be employed as "contract labour" in or in connec tion with the work of an establishment when he is hired in or in connection with such work by or through a contractor, with or without the knowledge of the principal employer;" "(c) "contractor", in relation to an estab lishment, means a person who undertakes to produce a given result for the establishment, other than a mere supply of goods or articles of manufacture to such establishment, through contract labour or who supplies contract labour for any work of the establishment and includes a sub contractor;" "(e) "establishment" means (i) any office or department of the Government or a local authority, or (ii) any place where any industry, trade, business, manufacture or occupation is carried on;" "(g) "principal employer" means (i) in relation to any office or department of the Government or a local au thority, the head of that office or department or such other officer as the Government or the local authority, as the case may be, may specify in this behalf, (ii) in a factory, the owner or occupier of the factory and where a person has been named as the manager of the factory under the , the person so named, (iii) in a mine, the owner or agent of the mine and where a person has been named as the manager of the mine, the person so named, (iv) in any other establishment, any person responsible for the supervision and control of the establishment.