130 - Interchangeable parts

I'm David Veech and this is Elevate Your Performance

We're continuing the conversation about the industrial revolution, bringing us from the craft manufacturing age to the mass manufacturing age.

The most significant enabler of mass production is the concept of interchangeable parts.  Throughout history to this point, craftsmen created individual parts for something, by forging or by milling, and then by filing and fitting two or more parts together.  You can imagine the extra time this takes to make things fit together precisely enough to function.

In 1785, a gunsmith from Avignon France named Honore Blanc built 50 Locks - the firing mechanism for a Flintlock Musket - the most advance firearm of the day and put on a demonstration for a small group of people where he quickly disassembled half of them, tossing each component part into separate boxes, mixing them all together.  

He then pulled parts at random from the boxes and began reassembling the locks, all of which worked perfectly.  This is apparently the first demonstration of the feasibility of interchangeable parts.  If all the parts were uniform, think how much more quickly we could repair damaged firearms, or sewing machines, or harvesters.

In the audience that day, among the angry gunsmiths (who's livelihood was clearly threatened with this new way of manufacturing) was the Minister to Paris from the newly established United States of America, Thomas Jefferson.  Jefferson wrote to the continental congress about this exciting new possibility and was promptly ignored.  Those angry gunsmiths, by the way, made sure that Blanc's workshop was destroyed when his patrons were killed during the French revolution in 1789.  He died in debt.

In the US, Eli Whitney invented the cotton gin in 1793.  According to the Patent Act of 1793, the US Department of State was responsible for processing patent applications.  In 1793, Thomas Jefferson was the US Secretary of State who received Whitney's first patent application letter.  Jefferson, whose plantation in Virginia produced a significant amount of cotton, was so interested in the cotton gin patent that he sent a letter back to Whitney asking for details and a model, or perhaps could he purchase a small gin for use on his "family farm."

Fast forward a few years.  It's 1797.  France is making noise about war with the US.  President Washington is concerned that the two national armories have only been able to produce 1,000 muskets in the last 3 years.  So the government solicits 40,000 muskets from independent gunsmiths in the US.  26 contractors bid on 30,200, and Eli Whitney gets a contract for 10,000, without a factory, a design, or any history of making firearms.  I guess then as now it pays to have a customer in the Vice President's office.

Where Blanc spent extra time hand finishing all the locks he made so they were as close to identical as possible, Whitney planned to build a machine that would produce identical parts.  His contract required delivery of the 10,000 muskets in 2 years, but it actually took him 10 years, but the significant result was Whitney's Milling Machine.  Because of his legal experiences with the Cotton Gin, Whitney never patented the milling machine or any other of his inventions.  

Stick around for how this had a significant impact on manufacturing throughout the 19th Century and even contributed to the second industrial revolution.