| 1921 ELLIS Hog House Design Patent 9036 |
| 1921 TRACY Sectional Individual Hog House Patent |
| 1921 BUTE WILLIAM Knockdown Hog Crate Patent |
| 1921 MILLER HARRY Hog Trough Patent Print Art |
| 1921 DENO FRED Hog Chute Patent Print Art |
| 1921 LUNDENE OTTO Hog Catcher Patent Print Art |
| 1921 MARTIN JAMES Hog Waterer Patent Print Art |
| 1921 HAISLEY CHARLES Hog Oiler Patent Print Art |
| 1921 ROBERT ROETHLISBERGER Hog Ring Patent |
| 1921 ARTHUR MORRISON Hog Feeder Patent Print Art |
| 1921 FRANK FOUTS Hog Feeder Patent Print Art |
| 1921 MAXWELL ROY Hog Feeder Patent Print Art |
| 1921 CHARLES HUNNICUTT Hog Feeder Patent Print |
| 1921 MACIEJEWSKI Hog Feeding Device Patent |
| 1921 HOWARD PAGE Hog Feeder Patent Print Art |
| 1921 CURRAN JAMES Hog Oiler Patent Print Art |
| 1921 RINER Sectional Hog Feeder Patent Print Art |
| 1921 GAINES BERNARD Hog Holder Patent Print Art |
| 1921 RALPH Automatic Hog Feeder Patent Print Art |
| 1921 ORR SAMUEL Hog Ring Patent Print Art |
| 1921 MCCOLLOUGH WILLIAM Hog Waterer Patent Print |