The Graham Hall Test

Shaking a load (e.g. boxes, furniture) after tying it to a trailer, to assess if it is sufficiently secured. To pass the Graham Hall Test: when you shake the load, it should also shake the trailer. If not, then you haven't secured your load properly, and you should consider re-tying it.

That Lawnmower definitely passes the Graham Hall Test; When you shake the mower, the trailer shakes too!

Let's do the Graham Hall Test, to make sure my fridge won't fall off.