In hte museum, I've put everything in the cannon and thought the rope would be the fuse, but apparently not... and using the torch directly doesn't work.  Could you give me a hint as to what I'm missing?  

Let's de-fuse the situation, ho ho! Have you took a look at one of the fun things to do at the museum? 

I've looked at everything and tried every interaction I can think of, no joy... I have the torch, rammer, rope, keys and screwdriver (plus Thomas Tew key and book).

HELP!

Omg sorry I didn't realise you had replied! 

Have you checked out the RC boat outside? It might contain something useful! 

Ah never realised there was more you could do with that... thanks!