Section 4924. Where the patentee of any invention or discovery, the patent for which was granted prior to the second day of March, eighteen hundred and sixty-one, shall desire an extension of this patent beyond the original term of its limitation, he shall make application therefor, in writing, to the Commissioner of Patents, setting forth the reasons why such extension should be granted; and he shall also furnish a written statement under oath of the ascertained value of the invention or discovery, and of his receipts and expenditures on account thereof, sufficiently in detail to exhibit a true and faithful account of the loss and profit in any manner accruing to him by reason of the invention or discovery. Such application shall be filed not more than six months nor less than ninety days before the expiration of the original term of the patent; and no extension shall be granted after the expiration of the original term.