| Patents Granted on 1820-05-?? |
Patents 1 -
7
of 7
      |
| Number | Date | Patentee | Title | Type |
| FX-3,200 | May 03, 1820 | N. Winslow | Cooking stove | stoves |
| 3,200X | May 03, 1820 | J. Butters, E. Howard | Machine for splitting leather | splitting and shearing machinery |
| 3,201X | May 03, 1820 | I.L. Skinner | Machine for excavating canals | |
| 3,202X | May 04, 1820 | S. Keplinger | Machine for making watch chains | chain making machines |
| 3,203X | May 08, 1820 | N. Read | Corn cracker, or hominy mill | miller |
| FX-3,203 | May 17, 1820 | S. Ives | Machine for making candle wick | candle making machinery |
| 3,205X | May 24, 1820 | S. Howard | Improved mode of towing boats | nautical propulsion apparatus |
