Figure 67 comprises three photographs of a full size model of an aircraft engine labelled 'a', 'b' and 'c'. Photograph (a) is a three quarter view of the engine from a distance. The casing looks circular and the fan blades visible at the front of the engine look smooth. Photograph (b) is a close up view of the fan blades at the front of the engine. It is now evident that the blades are made of little bricks and the edges and surfaces are jagged. Photograph (c) is another three quarter view of the engine from a distance. This time there are people studying the detail of the model showing that the diameter of the engine is around 1.5 meters.