The original field notes shall be a part of the record required to be kept by the county surveyor and the books containing the notes shall be kept with the surveyor’s other records of the county. Whenever one of the field books is filled or whenever a deputy county surveyor shall have ceased taking notes in the book the deputy has been using, the book shall be deposited in the office of the county surveyor or county auditor. Whenever the term of office of a deputy county surveyor expires, the deputy shall turn over to the county surveyor the field books which the deputy has partly filled.