US1511643A Hydraulic classifier Google Patents
HYDRAULIC CLASSIFIER. Application filed October 21, 1921. Serial No. 509,317. To all whom it may concern Be it known that I, LAMARTINE C. TRENT, a citizen of the United States, residing at Washington, in the District of Columbia, have invented certain new and useful Improvements in a Hydraulic Classifier, of which the following is a specification.