Just after the turn of the century, after many struggles, the heavier-than-air flying machine first rose from the earth, part of the success being due to the development of the comparatively light internal combustion engine. The materials of the airframe being mainly wood, including bamboo, and a few pieces of mild steel plate.

For a few years the materials of construction altered only a little and the knowledge of those materials and their behaviour was limited and confined to that which had been established during the course of mechanical engineering.

The mechanical engineers had been able to include fairly substantial factors of safety in their calculations which covered many variations and possible errors in materials, loads and workmanship and also—probably unknowingly —problems which could arise from fatigue.