OneGuyFromBarlick

You boil up a little water in the bottom hemisphere until plenty of steam is coming off, then put on the top hemisphere, making sure it doesn't leak around the joins. Allow the steam to condense and you have a partial vacuum - how partial depends on how well you displaced air with steam. Then you do the test with the weights to try and pull them apart, showing the power of air pressure to hold them together. We're like crabs and fish that live at the bottom of the sea. They're under pressure from all that weight of sea water above them. We're under pressure from all the weight of air stacked up above us.

Between you you have all got there. Look at THIS Wikipedia article on the Magdeburg Hemispheres. It describes the original demonstration using two teams of horses. Brilliant and fundamental discovery that triggered the atmospheric steam engine eventually.



What's this, who invented it and how is it connected to the development of the steam engine.

An early pressure cooker?

Correct Maz but this is very famous and a bit special (In some circles). I need more than that. Sorry!

Is it the automatic pressure release mechanism that you're looking for?

No Peter, it's the complete article. As I say, it's very famous in my circles as it was the first time high pressure steam was used. Clue, not Louis Pasteur!

If there's no reply by tomorrow I'll knock it on the head...

Is it an early autoclave used for sterilising things like surgical instruments?

A steam digester


From wiki
Denis Papin FRS (22 August 1647 – 26 August 1713) was a French physicist, mathematician and inventor, best known for his pioneering invention of the steam digester, the forerunner of the pressure cooker and of the steam engine.

Exactly right Kev. Most importantly it drew attention to the possibilities of high pressure steam and one man who took notice was Richard Trevithick who made the first high pressure steam engines. Watt never trusted high pressure.
Next one...

What is this?

Pollen?

chinatyke wrote: ↑31 Jul 2020, 12:50Pollen?

I'll go with that too. Gets right up my nose this time of year.

That didn't last long did it! I was hoping you would get side tracked into Covid virus... Will retreat and have a think.

Yes it's a loaf of bread but can you tell me what container it was baked in....?

A round tin?

I reckon it's something that was mentioned on another thread recently, a chicken brick?
First time I'd ever heard of one

I would agree with that Kev, not quite uniform enough for baked in a standard oven. Nice loaf anyway Pete.

By eck that didn't last long.....!
It was done in a chicken brick
(I thought I was being a bit clever there but never mind......)

Wow, I've impressed myself there. Nice looking loaf

I wouldn't have got it, as Kev says, nice bread!

The last one was so quick, I missed it.
Must have been .

Same here Cathy!

Boxes are always interesting! What's inside this one?

Shoe shine equipment?