GPT on Question 21, Sep 27

In the 18th century, black powder was increasingly manufactured in specialized powder mills, rather than simply mixed by hand. It consisted of potassium nitrate (saltpeter), charcoal, and sulfur, but good performance depended heavily on refining and mechanically processing those materials.

A typical mill worked broadly as follows:

• 1.Preparing raw materials
• •Saltpeter was obtained from imported deposits or extracted from nitrate-rich earth and then purified by dissolution and recrystallization.
• •Sulfur was melted or distilled to remove impurities.
• •Charcoal was made from selected woods—often willow, alder, or buckthorn—under restricted air.

• 2.Grinding and incorporating
  The ingredients were separately reduced to fine material, then combined in an “incorporating mill.” Heavy wooden or stone wheels, or stamp-driven pestles, worked the dampened mixture for an extended period. Moistening reduced airborne dust and helped the ingredients combine more uniformly.

• 3.Pressing and corning
  The incorporated mass was compressed into dense cakes. These were broken into grains in a process called corning. Earlier “serpentine” powder was simply a loose meal and tended to separate during transport; corned powder was stronger, more consistent, and easier to handle.

• 4.Grading and glazing
  Sieves separated grains by size for different uses, such as muskets, cannon, pistols, or priming. Grains might then be tumbled or “glazed” to round them, remove loose dust, and improve resistance to moisture.

• 5.Drying, proofing, and packing
  Powder was dried in dedicated buildings, tested for consistency and strength, and packed in barrels or smaller containers.

Because accidental ignition was common, mills were usually built away from towns, often along streams that supplied waterpower. Separate stages occupied lightly constructed, widely spaced buildings so that an explosion in one would be less likely to destroy the entire works. Workers used non-sparking tools, avoided exposed iron where possible, and followed strict rules about fire, footwear, and clothing.

This is a historical overview rather than a practical manufacturing guide; making black powder is extremely hazardous and is heavily regulated in many jurisdictions.