| All Patents in class 33/369 |
Patents 1 -
10
of 10
      |
| Number | Date | Patentee | Title | Type |
| 31,987 | Apr. 09, 1861 | R.B. Light | Machinist's Square | squares |
| 73,391 | Jan. 14, 1868 | H. Schüssler | Chain-Inclinometer | inclinometers |
| 341,378 | May 04, 1886 | W.E. Gwyer | Spirit Level for Boring Bits | levels |
| 360,247 | Mar. 29, 1887 | E. Reichenbach | Leveling Instrument for Grading Ditches | surveying apparatus |
| 371,294 | Oct. 11, 1887 | G. Woods | Plumb Level for Boring Bits | levels |
| 691,631 | Jan. 21, 1902 | J.H. Jackson | Spirit Level | line levels |
| 1,000,512 | Aug. 15, 1911 | I.L. Griswold | Line Level | line levels |
| 1,369,652 | Feb. 22, 1921 | F.B. Hall | Octagon Line & Surface Level | line levels |
| 1,716,744 | Jun. 11, 1929 | A.L. Stowell | Line level | line levels |
| 2,014,709 | Sep. 17, 1935 | F.A. Volz | Line Level | line levels |
