After the aircraft had been airborne about 90 minutes, the engine began to run roughly. The pilot's attempts to restore full power were unsuccessful and the engine stopped. During the latter stages of the subsequent landing roll, the aircraft struck a dead tree and damage was caused to the left wing and lower engine cowl. Before commencing the flight the pilot had checked the fuel contents gauges, they indicated that both tanks were about half full. He did not, however, visually check the fuel quantity in each tank nor did he specifically plan the duration of the flight. The loss of engine power was caused by fuel exhaustion.