Jason Crawford

So this demonstration was performed perhaps among other times in 1654.

According to Wikipedia, 30 horses in two teams of 15 could not separate the hemispheres until the valve was opened to equalize the air pressure.

And then, of course, they just fall apart.

So this demonstration was performed in the mid-1600s.

So this kind of basic scientific principle was known that early.

In fact, it is believed that Thomas Newcomen corresponded with scientists through the Republic of Letters, wrote letters to each other, including Robert Hooke.

And there is a report, although this is unconfirmed, that Newcomen discussed his steam engine that he was trying to invent with Hooke and that Hooke specifically advised Newcomen to operate the steam engine entirely by means of a vacuum.

I believe that someone else refers to this letter and says that this exchange happened, but we've never actually found the letter.

So chalk this up as unconfirmed.

But there are some other connections between science and steam that are known and established.

So decades later, James Watt is looking into the steam engine and he makes a famous contribution.

So Watt did not invent the steam engine, but he invented a new and much more efficient version of the steam engine.

In brief, what was going on was I mentioned that in Newcomen's engine, the steam was condensed in the piston.

The problem with this is you have to cool down the piston to condense the steam and then heat it up again.

So the entire piston, which is very large, is getting cooled down and heated up every cycle.

Watt came up with an idea that you could...

Cycle the steam through two chambers, a cold chamber where it got steam got condensed and then a hot chamber where it was expanded.

And you didn't have to then keep cooling and heating the same thing.

So it's a lot more efficient with fuel.

This is known as the separate condenser.