In counties where the original wills on file in the office of the clerk of superior court, and will books containing copies, are lost or destroyed, if the executor or any other person has preserved a copy of a will (the original being so lost or destroyed) with a certificate appended, signed by a clerk of the court in whose office the will was, or is required to be filed, stating that said copy is a correct one, this copy may be admitted to probate, under the same rules and in the same manner as now prescribed by law for proving wills. The proceedings in such cases shall be the same as though such copy was the original offered for the first time for probate, except that the clerk who signed such certificate shall, on oath, acknowledge his signature, or in case it appears that he has died or left the State, then his signature shall be proved by a competent witness; and the witness or witnesses to the original, who may be examined, shall be required to swear that he or they signed in the presence of the testator and by his direction a paper-writing purporting to be his last will and testament. (1868-69, c. 160, s. 1; Code, s. 57; Rev., s. 329; C.S., s. 368.)