We gave the sample spring this shot treatment and sent it back to the makers for a test. To their surprise, instead of breaking when it was flexed 2,000 times, they found that it would now withstand more than two million such cycles without breaking - an improvement of 100,000 per cent. Although this high per cent improvement was an exception, gains of 50, 100 or 500 per cent on various parts are now quite common. Yet, all we did was to question the theory of the polished surface, and apply a modern version of a very old art. This new information turned out to be of great value in the war. We know, for example, that engineers are constantly trying to increase the power of airplane engines without increasing their weight. This means that engine parts must be made stronger to carry greater loads. On many pieces, shot blasting was a simple and quick way. Now some engine parts that formerly developed a thousand horsepower are carrying a 50 per cent greater load. No weight has been added. They have simply been given this new treatment. And, as in the case of the Romans and the Celts, this improvement in weapons might mean the difference between a defeat and a victory. |