During cruise flight at 2,000 feet msl, the pilot of an amateur built Fisher Celebrity noticed that the airplane began to vibrate. He applied carburetor heat, and then checked the magnetos to see if they were functioning properly, but the vibration persisted. Moments later the vibration became worse, and the wooden propeller came apart. The pilot shut down the engine and executed a forced landing in a field. After touchdown, the landing gear collapsed, and the airplane was substantially damaged. The pilot had recently purchased the airplane. He had flown it for approximately 55 minutes, prior to the accident. According to the pilot, the airplane's original logbooks had been "misplaced" and new ones were begun prior to the sale. The airplane total time in service was estimated to be 190 hours. No entries regarding propeller inspections or propeller maintenance were noted in the new logbooks.