Prior to DEPARTURE the pilot checked the fuel quantity using a graduated dipstick, marked in litres and gallons. He noted that there was apparently sufficient fuel for the proposed flight. About 75 minutes after take-off and while cruising at 4500 feet amsl the engine lost all power. The pilot was committed to a forced landing in a rugged, heavily timbered area. The landing gear was sheared off on touchdown and deceleration forces were severe. Subsequent investigation revealed that the engine failed from fuel exhaustion. The pilot had not flown this particular aircraft before and was unfamiliar with the dipstick graduations. He misinterpreted the quantity indicated on the dipstick litres scale as gallons and whilst dipping the tanks his eye level was such that he could not see the fuel level within the tanks. During the flight the pilot had placed little reliance on fuel gauge indications.