Section 11
SEC. 11. The books and accounts of the grantee, his lessees, successors or assigns shall at all times be open to inspection and examination by the Insular Auditor or his duly authorized representative, and after beginning the operation of said tramway, it shall be the duty of the grantee, his lessees, successors or assigns to send to the Insular Auditor and the Director of Public Works quarterly reports, in duplicate, showing the gross receipts and all expenses made on account of the tramway, and any other data that may be required by the Insular Auditor or the Director of Public Works, who shall keep the same on file.