Computers and nonnuclear experiments, they stress, are no substitute for underground nuclear explosions meant to test complex designs.

Breadboards, perfboards or stripboards are common for testing new designs.

Modern engineering design makes extensive use of computer models to test designs before they are manufactured.

There he would pit his creations against each other to test his tactics and designs.

In 1858, The Mint tested new designs for the cent.

That alone would require trillions of calculations as engineers recast their models to test different designs.

The Navy tested various designs of propulsion machinery during the transition to steam power in the early 19th century.

He learned about their design dynamics and began testing designs of his own.

And engineers are making remarkable progress on computer simulations to test designs under conditions beyond the abilities of even the most sophisticated tunnels.

Besides testing new designs, his responsibilities including public demonstrations of military aircraft and participation in air races.