I wonder if for the benefit of listeners who might not know a whole lot about patent law, maybe, Michael, if you could kind of give a brief overview of sort of the smallest version you can of kind of how patent law works now and how it was different during the period that you all are writing about in this book.

Sure.

So interestingly, the things that are required to get a patent have not really changed that much since 1790.

So in order to get a patent, one must have a new and useful invention.

One must describe what the invention is and enable those who have skill in that area to make and use it.

And that was true in 1787.

I mean, 1790.

And I'm sure that if you started looking under rocks, you'd find a lot more.

So tell us, what are the ex-patents? Why are they even called that? And how could records of nearly 10,000 of them disappear?

So it's interesting you say that because we actually debated the title of the book because we were worried people would think of the X patents or I mean, the X files or something else when we were talking about it.

So from 1790 to 1836, we had a patent system.

And during that patent system, everything was done by hand.

Obviously, there was no technology.

There were no hard disks, etc.

And for almost all of that, you could send an application in and the patent would not be examined.

You know, what law was governing the patent system then? And what would you say were some of the strengths and the weaknesses of that law?