This is 99% invisible. I'm Roman Mars.

It's summertime in New York. The year is 1902.

And the second and Wilhelm's printing company in Brooklyn has a problem.

That's producer Emmett that's Gerald.

They're trying to print the popular humor magazine, Judge.

And it's really hot and there's a lot of humidity and they're having trouble

getting the inks to set properly on the page.

This is writer Stephen Johnson, author of the book How We Got To Now.

He says the problem isn't so much the heat, but the moisture in the air,

which was warping the paper and throwing the print out of alignment.

And so they hire a young, enterprising engineer by the name of Willis Carrier

to solve this problem and basically pull the moisture out of the air inside the printing plant.

And Carrier develops a system that pumps air over cold metal coils.

And it works. It pulls the moisture out of the air and the magazines are printed

more efficiently and the inks don't run.

But it has a side effect of as it's pulling the moisture out of the air.

It also makes the air cooler.

And so of course, everybody wants to have lunch in the room with his new machine.

I heard he's like, well, this is so nice in here. I would have bring my sandwich and sit

next to the printing press because it's the air is so much more pleasant.

Carrier had invented air conditioning and he began to think that maybe his new technology

could do more than just keep paper dry.

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