Materials & Chemistry
Tracks
Each track is one line of development climbing the eight levels. A cell holds the step written at that level; cross-listed steps have their home in another sector and are shown here because this subject depends on them. Dashed cells are planned and not yet written; blank ones have nothing planned.
Fibres, textiles and leather
Cord, thread, cloth and leather.
Ceramics and glass
Containers, fired pottery and the kiln, brick and tile, then glass.
Metals
Smelting, steel and heat treatment, the blast furnace, and electrolytic light metals.
Binders
Lime for mortar, plaster and whitewash, then hydraulic lime, pozzolana and cement.
Chemicals
Salt and fermentation, acids and alkalis, then synthetic nitrogen and polymers.
Everything in Materials & Chemistry
Gathered from the steps above: the guides and builds that serve them, the reference sheets those carry, and every book the steps, guides and builds cite.
Field guides
A dozen knots cover almost everything. Two of the most familiar ones — the reef knot and the granny — have killed people who used them for the one job they cannot do.
Level 1Cloth is a chain of slow jobs — growing, retting, spinning, weaving, finishing — and for all of history the slowest link was spinning. A weaver needed several spinners working full time to keep one loom supplied.
Level 0The highest calorie-return food source available to a group with nothing — and the one most often worked in the least productive way.
Level 0A trapline works all night while you sleep. A hunt works only while you are awake, usually returns nothing, and burns the calories it was supposed to find.
Level 1Animals turn grass nobody can eat into milk, meat, wool, leather, manure and traction. They also turn raw milk, a birthing ewe and a dog fed on offal into diseases that kill people.
Level 1Fired clay is the first material a group makes that does not exist in nature: a rock with a shape you chose. Getting there is mostly patience — in the drying, and in the heating.
Level 3Density, stiffness, expansion and melting point for the materials the ladder makes, and what each number decides.
Level 1How to build a dwelling that stays dry and standing for thirty years from subsoil, stone and timber: choosing the method, setting out, foundations, walls, roof, drainage, and how to inspect, repair and maintain it.
Level 3What matter is made of and how it changes: amounts, gases, acids, the energy and speed of reactions, electrochemistry, and the reactions every industry on the ladder runs on.
Level 2How to tell the ores that matter with nothing but a streak plate, a knife and your hand: colour lies, streak and weight do not.
Level 2Throw away two-thirds of the energy in a pile of wood and what is left is the only fuel that reaches the temperature of molten iron.
Level 2Iron is shaped by colour. Read the heat right and a bar of scrap becomes a chisel that holds an edge; read it wrong and it cracks, burns, or stays as soft as a nail.
Level 1The poisonings a rebuilding community is most likely to meet: where each comes from, how it shows, and the first thing to do.
Level 5Not a source of energy but a way of carrying it: make it, move it, store it — and know exactly how it kills.
Level 2Burn a rock, add water, and it turns back into rock in the shape you gave it. Mortar, plaster, whitewash, soap and tanning all start there — and so does an alkali burn that can blind in seconds.
Level 1What a soil is made of, why its acidity matters, and how to read a nutrient shortage in the leaves before it costs a harvest.
Level 1A glut eaten in the week it arrives is a feast. The same glut dried, salted, fermented or cellared is the difference between March and a famine.
Level 3The two dozen that decide who lives where there is no doctor: what each does, how it spreads, what kills it and which step stops it.
Level 3The basic set from the WHO list: what each treats, what it is made from, and the earliest tier that can make it. No doses, on purpose.
Level 3Fourteen branches, each with the handful of results a civilization cannot rebuild without, and where to learn the rest.
Builds

A woven basket that fishes all night while you sleep — the highest return-per-hour food gear in tier 0.

A wall of near-invisible mesh that fishes a whole channel while you do something else.

Continuous forced air — the component that decides whether you get metal or roasted rock.

The first machine that holds a temperature — pottery, brick and tile, and the training ground for every furnace above it.

A fireplace that throws its heat into the room and a lined flue that takes every trace of smoke out of the house: the part of a house most likely to burn it down or poison the people in it.

Burn limestone into quicklime — mortar, plaster, whitewash, flux, tannery liquor and soil correction, from one shaft.

A glass bead the size of a pinhead magnifies 150–350 times: enough to see yeast, blood cells and the larger bacteria that cause disease.

Two lenses in a tube: a 1-metre objective and a 25 mm eyepiece give 40×, enough to see Jupiter's moons and the phases of Venus.

A clay shaft that turns rock into iron — the first machine that makes every other machine possible.

Turn wood into the fuel that reaches smelting heat — no kiln, no metal, just a stack, a cover and a week of attention.

A controlled hot spot you can hold a bar in — the hearth every other trade's tools come out of.

Clean drinking water with no chemicals, no power and no moving parts — the highest lives-saved-per-effort structure on this site.
Reference sheets
Drawn overview sheets, each with its corrections printed under it. They orient; they are never the thing you identify from.
Books and archives
- The Story of Rope Plymouth Cordage Company · Gutenberg #71807
- The Use of Ropes and Tackle Homer J. Dana and W. A. Pearl · Gutenberg #56585
- Hand-Loom Weaving Mattie Phipps Todd · Gutenberg #31630
- Textiles William H. Dooley · Gutenberg #24077
- Vegetable Dyes Ethel Mairet · Gutenberg #24076
- How to Make a Shoe Jno. P. Headley · Gutenberg #25013
- A Text-book of Tanning H. R. Procter · Gutenberg #56601
- The Dyer's Guide Thomas Packer · Gutenberg #53797
- Wikipedia, offline (Kiwix ZIM) Archive · ~110 GB full with images · ~55 GB no-image · ~5 GB 'best of'
- CD3WD appropriate-technology archive Archive · ~13 GB
- FAO agricultural documents Archive · ~10 GB
- Hesperian Health Guides Archive · ~50–400 MB
- Bee Hunting John R. Lockard · Gutenberg #34044
- The Mechanical Properties of Wood Samuel J. Record · Gutenberg #12299
- WHO water, sanitation and health guidance Archive · ~200 MB
- The Survivor Library Archive · ~100 GB
- A Treatise on Sheep Ambrose Blacklock · Gutenberg #38189
- Poultry: A Practical Guide Hugh Piper · Gutenberg #38606
- Special Report on Diseases of the Horse United States Bureau of Animal Industry · Gutenberg #23403
- Special Report on Diseases of Cattle United States Bureau of Animal Industry · Gutenberg #30310
- Seat Weaving L. Day Perry · Gutenberg #53288
- De Re Metallica Georgius Agricola (tr. Herbert Hoover) · Gutenberg #38015
- Forge Work William L. Ilgen · Gutenberg #53854
- Practical Forging and Art Smithing Thomas F. Googerty · Gutenberg #69488
- How to Make Pottery Mary White · Gutenberg #64281
- Pottery, for Artists, Craftsmen and Teachers George J. Cox · Gutenberg #38248
- The Natural History of Clay Alfred B. Searle · Gutenberg #43297
- The Science of Brickmaking George F. Harris · Gutenberg #60550
- Concrete Construction: Methods and Costs Halbert P. Gillette · Gutenberg #24855
- Firemen and Their Exploits F. M. Holmes · Gutenberg #50575
- Glass Manufacture Walter Rosenhain · Gutenberg #52724
- A Handbook of Laboratory Glass-Blowing Bernard D. Bolas · Gutenberg #32962
- The Art of Glass-Blowing T.-P. Danger · Gutenberg #55266
- On Laboratory Arts Richard Threlfall · Gutenberg #22784
- Appropedia Archive · ~4 GB
- OpenStax textbooks Archive · ~2 GB
- Creative Chemistry Edwin E. Slosson · Gutenberg #17149
- Cottage Building in Cob, Pisé, Chalk and Clay Clough Williams-Ellis · Gutenberg #32048
- Shelters, Shacks and Shanties Daniel Carter Beard · Gutenberg #28255
- Practical Farm Buildings: Plans and Suggestions Andrew Frederick Hunter · Gutenberg #65618
- LibreTexts Archive · ~15 GB
- Elements of Chemistry, In a New Systematic Order, Containing all the Modern Discoveries Antoine Laurent Lavoisier · Gutenberg #30775
- The Chemical History of a Candle Michael Faraday · Gutenberg #14474
- Fireplaces and Chimneys Arthur H. Senner · Gutenberg #48378
- Essays; Political, Economical, and Philosophical — Volume 1 Benjamin Thompson, Count Rumford · Gutenberg #1025
- Chimneys and Fireplaces A. M. Daniels (USDA) · Gutenberg #48360
- Acids, Alkalis and Salts George H. J. Adlam · Gutenberg #50552
- The Microscope: Its History, Construction, and Application Jabez Hogg · Gutenberg #61233
- The Fundamentals of Bacteriology Charles B. Morrey · Gutenberg #43227
- The Telescope Louis Bell · Gutenberg #53740
- On the Construction of a Silvered Glass Telescope Henry Draper · Gutenberg #53542
- Modern Copper Smelting Donald M. Levy · Gutenberg #59328
- A Text-book of Assaying Cornelius Beringer · Gutenberg #18751
- Non-Technical Chats on Iron and Steel La Verne W. Spring · Gutenberg #73090
- The Working of Steel: Annealing, Heat Treating and Hardening Fred H. Colvin · Gutenberg #20282
- Steel William Metcalf · Gutenberg #71782
- Modern Machine-Shop Practice (Vols I & II) Joshua Rose · Gutenberg #39225
- Encyclopædia Britannica, 11th edition (1911) Archive · ~1–8 GB depending on format
- Safe Foundry Practice Travelers Insurance Companies · Gutenberg #77246
- Hawkins Electrical Guide, Vol. 1 Nehemiah Hawkins · Gutenberg #38384
- Lead Smelting and Refining Walter Renton Ingalls · Gutenberg #63784
- Soldering, Brazing and Welding Bernard E. Jones (editor) · Gutenberg #52074
- Electricity for the Farm Frederick Irving Anderson · Gutenberg #27257
- How to Make Electrical Machines R. A. R. Bennett · Gutenberg #44462
- The Boy Electrician Alfred Powell Morgan · Gutenberg #63207
- Water Power for the Farm and Country Home David R. Cooper · Gutenberg #62117
- The Young Mechanic John Lukin · Gutenberg #60765
- Concrete Construction for the Home and the Farm Atlas Portland Cement Company · Gutenberg #62312
- Plain Concrete for Farm Use T. A. H. Miller · Gutenberg #59379
- The Story of the Soil Cyril G. Hopkins · Gutenberg #4527
- USDA / NRCS soil and conservation library Archive · ~5 GB
- The Complete Distiller Ambrose Cooper · Gutenberg #65020
- Alcoholic Fermentation Arthur Harden · Gutenberg #44985
- The Complete Book of Cheese Robert Carlton Brown · Gutenberg #14293
- The Practical Distiller Samuel McHarry · Gutenberg #21252
- The Handbook of Soap Manufacture W. H. Simmons · Gutenberg #21724
- Principles and Practice of Agricultural Analysis: Fertilizers Harvey W. Wiley · Gutenberg #72438
- Nitro-Explosives: A Practical Treatise P. Gerald Sanford · Gutenberg #15308
- Dictionary of Explosives Arthur Marshall · Gutenberg #50446
- Glue, Gelatine, Animal Charcoal, Phosphorus, Cements, Pastes and Mucilages F. Dawidowsky · Gutenberg #53363
- Pigments, Paint and Painting George Terry · Gutenberg #56344
- A Treatise on Grain Stacking John N. De Lamater · Gutenberg #34586
- The Elements of Bacteriological Technique J. W. H. Eyre · Gutenberg #27713
- Principles of Public Health Thomas Dyer Tuttle · Gutenberg #53974
- WHO, Immunization in Practice Archive · Free PDF download
- Merck's 1899 Manual of the Materia Medica Merck & Co. · Gutenberg #41697
- Elements of Arithmetic Augustus De Morgan · Gutenberg #68662
- The Filtration of Public Water-Supplies Allen Hazen · Gutenberg #69025
- Chlorination of Water Joseph Race · Gutenberg #37389
- Sewerage and Sewage Treatment Harold E. Babbitt · Gutenberg #61773