I posted the other day about the wooden kit for Stephenson's steam engine Rocket. As cool as that kit is, and as amazing as the original invention is, here is something perhaps even more amazing. This working model of Stephenson's Rocket was made by master glassblower Michal Zahradník.
No only does the model work when a fuel tablet is lit bellow a small boiler, but everything is made of glass: crankshaft, piston, counterweight, all of it. No gasket materials or sealants were used.
On the difficulties of making working piston in glass:
The piston is the most arduous part to make due to to extreme level of precision needed. Its parts have to be so accurate that no machinery is of use here. The piston and its cylinder must be hand sanded to perfection, and they are very likely to crack in the process! On average, three out of four crack.
For more info on Stephenson's Rocket, I highly recommend the book The Most Powerful Idea in the World: A Story of Steam, Industry, and Invention.
[ Thanks Catherine! ]