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