Section 5
SEC. 5. The grantee, his successors or assigns, shall keep c a separate account of the gross receipts of the telephone, telegraph and electrical transmission business ti ansacted by them in each of the municipalities of the provinces of Occidental Negros and Oriental Negros, and shall furnish to the Insular Auditor and the Insular Treasurer a copy of such account not later than the thirty-first day of July of each year for the twelve months preceding the first day of July. For the purpose of auditing the accounts so rendered to the Insular Auditor and the Insular Treasurer all of the books and accounts of the official inspection of the Insular Auditor, or his authorized representatives, and in the absence of fraud or mistake the audit and approval by the Insular Auditor of the accounts so rendered to him and to the Insular Treasurer shall be final and conclusive evidence as to the amount of said gross receipts.