The bird-cage's exterior is made of tungsten nearly as hard as diamonds. Its exterior is ribbed much like a screw and lies against the side of the big gear, turning at right angles io the gears rotation and cutting as it turns. With each revolution of the big gear, the little tungsten screw bites in, moking what is called the "rough cut." After this process has shaped the gear teeth to proper depth and thickness, the little tungsten teeth set to work on the finish to 3/10,000ths of an inch accuracy.
During all this time, the big gear must never cease turning. If the cutting job should stop, the slight change in position on restarting would ruin the gear. To make sure the motion never is interrupted, auxiliary engines are ready to take over the work of the main power plant if that fails.
Although the finishing is done by machine, the skill of the workmen also is indispensable, Mr. Ross points out. The gears cannot be made without the skill of human hands to guide the robots. Furthermore, it is not enough for the workman to be merely a "skilled" cutter; he must. be super-skilled to work within the '8/10000ths of an inch margin of perfection.
Imperfections greeter than that, when translated through a huge 35-ton cog-wheel, would be magnified enough to endanger the power transmission of a battleship,
Text read from the printed page and cleaned; old type leaves the occasional error.