Just stumbled on these by accident - while looking at info on Kites.
http://www.cochranes.co.uk
(Go to Secondary School and Further Education, then scrolldown to Mathematics, General Science and Technology, and click on 'Hyman Fire Piston').
These are designed for use in schools and physics classes to demonstrate the principle - however the best bit is that it is a clear firepiston, for around 30 pounds. The size looks like its probably about 10-12 inches long - but its difficult to tell from the picture.
If I had any spare cash I'd probably go and buy one just to see what its like - in the meantime I might see if there is anywhere else selling them under this 'use' banner for less...
http://www.cochranes.co.uk
(Go to Secondary School and Further Education, then scrolldown to Mathematics, General Science and Technology, and click on 'Hyman Fire Piston').
These are designed for use in schools and physics classes to demonstrate the principle - however the best bit is that it is a clear firepiston, for around 30 pounds. The size looks like its probably about 10-12 inches long - but its difficult to tell from the picture.
If I had any spare cash I'd probably go and buy one just to see what its like - in the meantime I might see if there is anywhere else selling them under this 'use' banner for less...