Wally:

I, too, have used gravity, fulcrims, levers, and moment arms to do seemingly impossible things.

However, several years ago I decided to move a small barn, by myself, from one side of the creek in my back yard to the other side. My first challenge was to get the barn moved away from a fence and turned in the direction I wanted to take it. To make that process a bit easier I chanied it to the front of my car and backed and turned it until it was pointed in the right direction. Then, after using fulcrums and timbers to get 2″ pipes under the skids on all four corners of the building I began to roll it in the direction I wanted to go. But I found the prying and rolling to be much tougher than I had expected.

After I had moved it just a few feet, at great effort, I stood back to rest — only to discover that I still had the barn chained to the front axel of my car. The car was in gear with the emergency brake set.

this is very interesting