A professional who controls series of vats that boil tanbark, quebracho, chemicals, and water to prepare tanning solution. Respnsibilities include:

• Weighs specified amounts of materials on scale and dumps them into vat.
• Opens valves to admit water and steam into vat.
• Adjusts steam valve to maintain solution at specified temperature.
• Tests sample of solution for specific gravity, using hydrometer.
• Adds materials to solution to obtain solution of specified gravity.
• Starts pump to transfer solution from vat to storage tank.
• May grind bark or wood, using grinding machine.