A professional who tends machines that dry, grind, and screen materials, such as sodium nitrate, apricot pits, sulfur, and clay for use in making dynamite. Respnsibilities include:

• Shovels or dumps materials into drier hopper and adjusts temperature of steam-heated drier to specified reading.
• Starts conveyors and elevators that convey materials through drier and grinder.
• Starts grinder and sifting screens that grind and screen materials and deposit them in bins.
• May drive scoop tractor to fill drier hopper.
• May test moisture content of ingredients, using carbide-filled jar and gauge that registers gas produced.
• May weigh out dried ingredients according to formula, to prepare batches for mixing with nitroglycerin.
• May be designated according to ingredient treated as soda-dry-house operator.