Make It · Book Three

Balance Beam

Twenty minutes, and everything in it came off a kitchen table. No glue, no fire, no tools. Every load on the Drover is weighed against the other side before Aunt Bess takes a step, because thirty pounds of difference makes her walk a curve, a curve becomes a rub, and a rub becomes a sore in three days. Nell does not need to know what either pannier weighs. She only needs to know they are the same.

Ink drawing of the finished build.
The finished thing, drawn the way the books draw an object.

You need

  • a wooden ruler or a paint stirrer
  • a pencil
  • two paper cups
  • tape
  • and two handfuls of dried beans
  • pasta or coins

About half an hour. Everything on that list came out of a kitchen, which is the rule these pages are written to.

Steps

  1. Lay the pencil flat on the table. Lay the ruler across it, crosswise, near the middle.
  2. Slide the ruler a little at a time until it balances level with nothing on it. Mark that spot. That mark is your fulcrum, and everything else depends on it.
  3. Tape a paper cup to each end, exactly the same distance out from the mark. Measure it. Do not guess.
  4. Drop a handful of beans in one cup. That end goes down. That is a loaded pannier.
  5. Add beans to the other cup, a few at a time, until the ruler sits level again. Stop. You have just made two loads exactly the same weight without knowing what either one weighs. That is the whole job, and it is what the beam in the Low Shop is for.
  6. Now move the pencil one finger-width off your mark and level it again. It takes a different number of beans on each side — same beam, same beans, different answer. That is why the panniers hang the same distance from Aunt Bess's spine, and why Nell measures it instead of eyeballing it.

Try this

Put something small in one cup — an eraser, a key — and count how many beans level the beam. Write the number on the cup in pencil, then do three more things. You have made a range card, and there is one painted on every rig in the Low Shop.

Be careful

Work in the middle of a table, not at the edge. Beans, pasta or coins only — nothing heavy, nothing glass, nothing that would hurt a foot if a cup went over. Dried beans and coins are the wrong size for small children: if there is anybody in the house who still puts things in their mouth, do this one where they are not.

Nothing points at a person.