Pete's words to Meade Lux Lewis's "Honky Tonk Train Blues" were famously inspired by an entry in an encyclopædia he had as a boy, describing the mechanical workings of a steam locomotive.

Now, for your instruction, we can present the very page:

I'm the original honky tonk train
I'm the one that you see when you're watching a western
That's me chugging by
Of the ones that you see in the films I'm the best 'un
I'll tell you why
'Cause no other loco can ever compare
With the places I've been 'cause I've been everywhere
And I never once stopped for a moment of restin'

And if my fire's burning properly the hot air oughta
Rise and go along a lot of tubes
That are surrounded by water in the boiler till eventually it moves
On down the engine's aorta out to the funnel where the cloud of smoke exudes

And now the hot air in the tubes has made the water in the boiler turn to steam -- hot hot hot
The steam also rises and collects inside that large symbolic dome at the top top top
But if you think that now the steam is just as hot as it is gonna get you're wrong 
     'cause it's not not not

Because this is where the driver opens up the regulator valve handle --
The steam becomes alive again and goes back through the boiler or can
Which I call it only 'cause I've a shortage of rhymes ending in -an

So having been through the superheater tubes the steam is hotter than ever it was before 
     the heat is more you may be sure the steam now
Passes on into the piston cylinder and pushes the piston for-
Wards and backwards by means of valves which reciprocate in alternation
According to simple mechanical law

The piston then pushes connecting rods fixed to the wheels, that are set on the rails
But that's not the end of the story 'cause then all that steam, as you will have seen
Is blown out as exhaust through the funnel whence it can expire
Thereby increasing the draught of the fire

So now apart from some rather superfluous detail which doubtless will seem to you obvious
     hardly worth saying
The story's over in its basic essentials -- the rest is merely overlaying
What you can see for yourself quite easily although I would just like to mention 
     the thing on the front
That always comes in handy when you want to catch cows