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 eighty days from the date when he obtained the certificate required by Section one of this Act and shall commence work under the supervision and subject to the approval of the electrical engineer of the Public Service Commission, in accordance with the plan, specifications, and estimates previously approved by the Public Service Commission, within six months' time from and after the date of filing such acceptance, unless prevented by an 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 date of such acceptance, and shall thereafter maintain a first-class electric light, heat and power service: Provided, That in consideration of the franchise hereby granted, the grantee shall pay quarterly into the municipal treasury of the municipality above-named one and one-half per centum of the gross earnings of his electrical business during the life of this franchise. And said tax shall be in leiu of any and all taxes of any kind, nature or description levied, established or collected by any authority whatsoever, municipal, provincial, city or national now or in the future, on its building, poles, wires, insulators, transformers, installations, conductors, and accessories, placed in and over and under all public or private property, streets bridges and public squares, and on his franchise, rights, privileges, receipts, revenues and profits for which taxes the grantee is hereby expressly exempted.