Every employer shall within four weeks of the date of publication of this part of the Agreement take out a policy of insurance with a registered insurance company which shall provide for payment to be made to all employees of the employer who are deprived of work, through fire, for the amount of two week"s wages: Provided that, should the stoppage of work be for a period of less than two weeks, a pro rata payment may be made. Should it not be possible for the employer to obtain such a policy of insurance, he shall deposit with the Council, an amount equal to two weeks" wages of all employees in the establishment at the date of coming into operation of this part of the Agreement which the Council shall retain in a special trust investments account until required for a like payment to employees. Any adjustment to the amount held by the Council shall be made within two weeks from the date of an increase or decrease, as the case may be, in the total number of employees employed by the employer.