Section 7
SEC. 7. Said grantee shall file his written acceptance of this franchise with the Secretary of Public Works and Communications within one hundred and twenty days from the date when he obtains the certificate required by section one of this Act, and shall commence work under the supervision of the district engineer, in accordance with the specifications, and estimates previously approved by Public Service Commission, within six month's time and after the date of filing such acceptance, unless Prevented by act of God or force majeure, usurped or military power, martial law, riot, or civil commotion or other inevitable cause, and shall complete the system and have the same in operation 'within eighteen months from the of such acceptance, and shall thereafter maintain a class water system and furnish first-class service to public and to private consumers: Provided, That in consideration of the franchise hereby granted, the grant shall pay quarterly into the municipal treasury of the municipality above named, one per centum of the gross earnings of his business during the first thirty years, and two per centum during the remaining twenty years of the life of this franchise.