Woodworking and the first machines

Air-drying takes roughly a year per 25 mm of thickness. Stack boards on level bearers off the ground, with stickers — spacers about 20–25 mm thick — every 40–60 cm, lined up vertically so boards do not bow. Roof the stack, leave the sides open to wind, and seal the end grain with wax, paint or pitch, or the ends split.

Weigh a sample board weekly. It is as dry as the air will make it when the weight stops falling. Green wood shrinks across its width as it dries — far more across than along — and destroys any tight joint made from it.

Riven wood follows the fibres, so it has no grain running out across the piece, and it is far stronger than sawn wood of the same size — which is why chair legs, spokes, tool handles and ladder rungs were riven.

Choose straight-grained, knot-free logs: oak, ash, chestnut and hazel rive well. Start the split with an axe or wedges on the end, then work down the length with a froe and mallet, levering to steer the split toward the thicker side if it runs off. Split radially — in halves, quarters, eighths — for stable pieces.

Without metal fastenings, joints hold by geometry and pegs. The core joint is the mortise and tenon: a tenon about a third of the thickness of the stock, fitting its mortise snugly by hand pressure.

Drawbore it: drill the peg hole through the mortise cheeks, assemble, mark the hole's centre on the tenon, take the joint apart, and drill the tenon hole 2–3 mm closer to the shoulder. Driving a tapered, riven peg through the offset holes pulls the joint tight permanently, and it stays tight as the wood moves. Pegs: riven, straight-grained, dry hardwood.

The shaving horse is a bench with a foot-operated clamp that holds work for a drawknife, leaving both hands free — the first workholding device, and it doubles output.

The pole lathe: a springy sapling pole 3–4 m long — ash or hazel — fixed above the lathe, a cord from its tip wrapped 2–3 turns round the work, down to a foot treadle. Press the treadle and the work spins toward you and you cut; release and the pole pulls it back. Tool rest close to the work, centres driven into the ends of the blank. See the pole lathe.

Gear teeth cut by eye bind and wear, and the machine fails. A dividing plate — a disc with rings of equally spaced holes and a pin — indexes the work round by exact fractions.

Make the plate large — 30 cm or more across. Any error in spacing the holes is scaled down in proportion on a smaller gear cut from it. Space holes by stepping round with dividers, adjusting until the last step lands exactly on the first, and choose hole counts with many factors — 60, 72, 96 — so one ring cuts many gears. This is your first encounter with the precision problem: the plate limits every machine you build from it.

A wooden screw turns rotation into enormous pressure — cider and oil presses, bench vices, clamps, and later the printing press.

Use close-grained hardwood — beech, boxwood, fruitwood — dry and knot-free. Lay out the thread with a paper strip wound helically round the blank, marking a constant pitch; cut and file along the line. Cut the matching internal thread with a tap made from the same pattern. Wax both. Coarse threads are stronger in wood than fine ones.

The pole lathe is the start, not the goal. In order of what they unlock:

• Frames for a loom and boards for bellows — cloth and metal.
• Wheels and axles — see wheel, cart and road.
• Gears and a mill frame — water power.
• Presses — oil, cider, cheese, paper.

Build each to drawings with written dimensions, so the second one is a copy rather than a second guess.

Many broadleaf species regrow vigorously from a cut stump, giving straight poles on a cycle — hazel about every 7–10 years, sweet chestnut about 12–20, oak and ash 20 years or more depending on the pole size wanted.

Cut in winter, while dormant, low and at an angle so water runs off the stool. Divide the woodlot into as many plots as the rotation has years and cut one per year, so every year's supply is the same. Keep deer and livestock out for the first 2–3 years — browsing the new shoots kills the stool.