" By section 2 (9) "employee" means any person employed for wages in or in connection with the work of a factory or establishment to which this Act applies and (i) who is directly employed by the principal employer on any work of, or incidental or preliminary to or connected with the work of , the factory or establishment, whether such work is done by the employee in the factory or establishment or elsewhere; or (ii) who is employed by or through an immediate employer on the premises of the factory or establishment or under the supervision of the principal employer or his agent on work which is ordinarily part of the work of the factory or establishment or which is preliminary to the work carried on in or incidental to the purpose of the factory or establishment; * * * * 145 By section 2(12)"factory "means any premises including the precincts thereof whereon twenty or more persons are employed or were employed for wages on any day of the preceding twelve months, and in any part of which a manufacturing process is being carried on with the aid of power or is ordinarily so carried on.