Need help in Level 8 (Steam)

[Hollie79]

This level looks rather complex, but I haven't gotten very far. I put one of the large boxes on one of the three pressure switches, but can't find anything else except a hatch to go down. Down there is a boiler, but I've nothing with which to burn and start the boiler. Suggestions?

Do you remember seeing boxes somewhere else? How can you get one of those boxes to the switches? =)

Spoiler below!

There are 2 boxes in the room with the ladder leading to the boiler. Put one box on top of the other and push them both so you can slide the second box into the hallway