Between the two ends of the beam is the fulcrum, or pivot point, which is the point at which the beam can balance and move freely up and down around. On one end, the user places the load to be moved.

It is not how they work at balance, it is why they don’t keep on moving until they hit the end-stops when they are out of balance. Finally, I worked it out all on my very own – for old-fashioned ...