| Patents Granted on 1820-08-?? |
Patents 1 -
10
of 10
      |
| Number | Date | Patentee | Title | Type |
| 3,221X | Aug. 03, 1820 | J. Deneale | Instrument for mapping lands | surveyor |
| 3,222X | Aug. 03, 1820 | R.P. Cunningham | Spiral helm wheel | |
| 3,223X | Aug. 12, 1820 | L. Thwing | Machinery for passing boats up rapids | nautical propulsion apparatus |
| 3,224X | Aug. 12, 1820 | J. Chittenden | Locks and latches, etc. | household tools |
| 3,225X | Aug. 12, 1820 | N. Haight, J. Haight | Making ingrained carpeting | |
| 3,226X | Aug. 15, 1820 | B. Cox (B. C. Hadley) | Washing machine | washing machines |
| 3,227X | Aug. 16, 1820 | D. Sellers, N. Sellers | Wire screens for cleaning rice | miller |
| 3,228X | Aug. 22, 1820 | A. Shattuck | Thrashing machine | miller |
| 3,229X | Aug. 23, 1820 | J. Gillaspie | Smut machine | miller |
| 3,230X | Aug. 30, 1820 | F. Class, R. Berrian | Open circular stove or fire place | stoves |
