Every technical innovation seems to require additional technical advances in order to make it fully effective. If one invents a lathe that can cut metal faster than existing machines, this necessitates improvements in the lubricating system to keep the mechanism running efficiently, improved grinding materials to stand up under the enhanced speed, and new means of taking away quickly the waste material from the item being turned.

The automobile is a prime example of how a successful technology requires auxiliary technologies to make it fully effective, for it brought whole new industries into being and turned existing industries in new directions by its need for rubber tires, petroleum products, and new tools and materials. Furthermore, large-scale use of the auto demanded a host of auxiliary technological activities - roads and highways, garages and parking lots, traffic signals, and parking meters.

A good case of invention mothering necessity can be seen in the landmark textile inventions of the 18th century. Kay’s &dquo;flying shuttle&dquo; wove so quickly that it upset the usual ratio of four spinners to one weaver; either there had to be many more spinners or else spinning had to be similarly quickened by application of machinery. Thereupon Hargreaves, Cartwright, and Crompton improved the spinning process; then Cartwright set about further mechanizing the weaving operation in order to take full advantage of the nowabundant yam produced by the new spinning machines.