After twenty years have elapsed from the date of recording a deed, lease, contract, agreement, mortgage or a release of part of mortgaged premises any such instrument so recorded which has not been returned to the person presenting such instrument for recording or to some other person authorized to receive the same, may be destroyed by the county clerk without the permission of the commissioner of education provided any such instrument is photographed, microphotographed or reproduced on film preserved for examination and use.
New York Legal Code