Felling, seasoning and joinery, the pole lathe and the first machines.
Make things accurately from wood, including the machines that will later work metal.
Needs first: A cutting edge, Permanent shelter (Shelter)
Every guide, build, reference sheet and book reached from the steps above.
The forest is the first material store, the first fuel supply and the first thing a group kills itself cutting down. Managed, it is also the only one of the three that grows back.
Level 3Turning the sciences into things that work: machines, structures, water in pipes and channels, heat through walls, and feedback control. Each result with what it lets you do and who first found it.
The first machine tool — a sapling, a cord and a treadle, and the direct ancestor of everything in tier 3.
A whole building balanced on one oak post so it can be turned to face the wind — the first machine that let a settlement mill grain where there was no falling water.