Phase 01 — First days: water, fire, shelter / About year 1
01.14
Hot-stone boiling pit
makes water safe to drink before pots exist
AWhat it needs
Needs 9 other products in all, 4 of them directly.
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- 01.14 Hot-stone boiling pitHome Year 1 needs 9 products
- 01.04 Digging stickMaking Year 1 needs 2 products
- 01.03 Sharp stone flakeMaking Year 1 needs 1 product
- 01.02 HammerstoneMaking Year 1 raw materials only
- 01.08 First fire and stone hearthMaking Year 1 needs 5 products
- 01.06 Tinder and kindling storeMaking Year 1 raw materials only
- 01.07 Bow-drill fire setMaking Year 1 needs 3 products
- 01.03 Sharp stone flakeshown above ↑← shown at left
- 01.05 Twisted plant-fibre cordMaking Year 1 needs 2 products
- 01.12 Bamboo cups and water tubesMaking Year 1 needs 2 products
- 01.13 Split-stick tongsMaking Year 1 needs 3 products
Open a box to see what it needs. A dashed box is a product already drawn in full: click it to jump there. In the org chart, drag to move around.
BWhy
Clear water can still carry sickness that kills. Boiling makes it safe. With no pot that can stand on a fire, the heat is carried to the water inside stones.
CYou need
DSteps
- Choose stones with care. Good: basalt, granite, other heavy dark even stone. Never use stones from the stream, flint, layered stone, sandstone or limestone. Wet or layered stones burst, flint shatters, and limestone turns into a powder that burns skin.
- Dig a bowl-shaped pit two hand-spans across and one hand-span deep, a few paces from the fire.
- Line it with wet clay, a finger thick, pressed on firmly and smoothed with a wet hand. Let it stiffen for an hour.
- Put the stones in the heart of the fire and keep it burning hard until they glow dull red in the dusk, about three quarters of an hour.
- Fill the pit three quarters full with water carried in bamboo.
- Lift a stone with the tongs, knock off the ash, dip it for an instant in a rinsing cup, and lower it into the pit. Do not drop it: it will break the lining.
- Add stones one at a time until the water boils hard. It takes six to ten.
- Keep it boiling hard for a slow count of one hundred, adding a stone whenever the boiling slackens.
- Lift the stones out and put them back in the fire. Let the mud settle, then dip the clean water off the top into bamboo bottles kept only for boiled water.
- Each person needs about three cooking tubes of water a day. For 24 people, run three pits in turn through the day.
EIt worked if
- The water reaches a hard rolling boil and holds it for the full count.
- After a week, nobody in the camp has loose bowels.
FWhat goes wrong
- A stone bursts in the fire. It was damp or layered. Dry new stones beside the fire for a day before heating them, and keep faces away.
- The water never boils. Too much water for the stones, or stones not hot enough. Use a smaller pit or more stones.
- Muddy water. The lining is breaking up. Re-line the pit and lower the stones gently.
- Boiled water gets dirty again. Someone put a used cup into it. Lift it out only with one clean dipper kept for that job, and keep the boiled-water bottles separate.
GSafety
- Steam and splashes scald. Lower stones at arm's length and keep everyone else well back.
- Drink nothing from the stream unboiled, however clear it looks.
HIn the story
On the third day two people are already sick from stream water. Grace stands in front of the council and says the words that become the first law of the island: nobody drinks water that has not boiled. Then she digs the first pit herself.
IFigures
