A professional who tends gas-fired kettle that removes gold, silver, and copper from black mud. Respnsibilities include:

• Shovels mud into kettle, and turns valve to admit acid until mud is covered.
• Rakes mud to dissolve gold and silver.
• Ladles solution into water-filled settling tank to precipitate gold and silver compounds.
• Removes precipitates and adds reagents to change their chemical composition.
• Heats precipitates in cupola furnace to extract gold and silver.
• Ladles remaining mud into tank filled with water and admits steam to dissolve copper.