In all cases where any owner or holder of a mortgage, having legal power to satisfy the same, has heretofore executed and delivered, or may hereafter execute and deliver, a power of attorney authorizing the recorder of deeds of the county in which such mortgage is recorded, in office at the time of such execution and delivery, by his official title to enter satisfaction of such mortgage upon the record, and such satisfaction has not been entered, such power of attorney when duly recorded shall be a sufficient authority to any subsequent recorder of deeds of the same county to enter satisfaction of such mortgage upon the record thereof.