| Patents for John M. Douglas |
Patents 1 -
10
of 14
      |
| Picture | Number | Date | Patentee | Title |
 | 19,834 | Apr. 06, 1858 | W. Douglas, B. Douglas | Portable pump |
 | 33,299 | Sep. 17, 1861 | B. Douglas | Pump stand |
 | 35,802 | Jul. 01, 1862 | B. Douglas | Improved side force-pump |
 | 38,444 | May 05, 1863 | J.W. Douglas | Improvement in pumps |
 | 56,671 | Jul. 24, 1866 | J.W. Douglas | Double acting pump |
 | 74,321 | Feb. 11, 1868 | J.W. Douglas | Improvement in pumps |
 | 81,611 | Sep. 01, 1868 | J.W. Douglas | Grindstone Frame |
 | 93,974 | Aug. 24, 1869 | J.W. Douglas | Knapsack fire extinguisher |
 | 97,767 | Dec. 14, 1869 | J.W. Douglas | Improvement in pumps |
 | 97,894 | Dec. 14, 1869 | J.W. Douglas | Improved apparatus for extinguishing fires by means of chemical agents |
