They used a square box for the base, put a heavy pot on a raised platform and then tied the rope to it over a beam.
They then realized they wouldn’t have enough wood for two similar structures until next week’s shipment from the lumber mill, so they just built a man sized square out of the remaining wood and set two of the criminals up on stones with a rope about their necks between them over the frame.
The last criminal was set up on the proper gallows.
When high noon came, the pot was dropped and the stones kicked away and the brothers were hanged.
Some people were incredulous as to how the second “gallows” could actually work.
The sheriff simply said, “Well, everybody knows that the square of the high pot and noose is equal to the sum of the squares of the remaining Slys.”