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American military camp
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American troop undergoing inspection
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Best sidehill harvester in operation on hillside in Washington state, pulled by many horses
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Caterpillar tractor pulling combines
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Digester at waste disposal plant in Madison, Wisconsin
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Digestors assembly with gas collector for Janesville, Wisconsin sewage disposal plant
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Flocculators and settling at sewage disposal plant in Madison, Wisconsin
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Grease tank/trap for sewage disposal plant at Madison, Wisconsin
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Holt sidehill combine powered by 5 men and 33 mules
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Holt sidehill combines at work on hillsides in Washington state