| Patents for John E. Hall |
Patents 16 -
25
of 25
      |
| Number | Date | Patentee | Title | Type |
| 233,488 | Oct. 19, 1880 | S. Darling | Art of Manufacturing Mathematical Instruments | |
| 235,133 | Dec. 07, 1880 | S. Darling | Micrometer Gage for Wire & Sheet Metal | micrometers |
| 241,879 | May 24, 1881 | E.L. Parsons | Gear Wheel Cutter | milling machine cutters |
| 252,436 | Jan. 17, 1882 | S. Darling | Metallic Try Square | try squares |
| 287,420 | Oct. 30, 1883 | S. Darling | Micrometer | micrometers |
| 289,512 | Dec. 04, 1883 | S. Darling | Graduated Measure of Length | rule graduations |
| 289,513 | Dec. 04, 1883 | S. Darling | Micrometer Gage | micrometers |
| 292,415 | Jan. 22, 1884 | S. Darling | Comparator | comparators |
| 370,379 | Sep. 27, 1887 | S. Darling | Pen Cleaner | draftsman |
| 376,430 | Jan. 17, 1888 | S. Darling | Protractor | protractors |
