Surveying and Levelling Instruments, Theoretically and Practically Described. For construction, qualities, selection, preservation, adjustments, and uses; with other apparatus and appliances used by civil engineers and surveyors in the field.

CHAPTER XIV.

Chapter 1417 wordsPublic domain

INSTRUMENTS OF REFLECTION:--Octant or Quadrant--Reflecting Circle--Sextant--Principle--Parallax--Construction--Examination-- Adjustment--Artificial Horizon--Sounding Sextant--Box-Sextant-- Supplementary Arc--Improvements upon this--Optical Square--Optical Cross--Apomecometer 422