Today, because of Whitney's ideas, most products are manufactured using standardised, interchangeable parts.
But even with this advance, manufacturers still faced the significant limitation that they could not produce a part unless they had seen or examined it firsthand.
Thanks to Gaspard Monge, a Frenchman of modest beginning, this soon changed.
Monge's greatest achievement was his book descriptive Geometry.
In it, he explained techniques for drawing three-dimensional objects on paper.
For the first time, precise drawings permitted manufacturers to make standardised, interchangeable parts without first examining a prototype.
Today, thanks to Monge, manufacturers rely on CAD (computer-aided design) and CAM (computer-aided manufacturing) to take three-dimensional designs straight from the computer to the factory floor.