DIY History | Transcribe | Scholarship at Iowa | Eccentricity of the Sextant by Frederic Furbish, 1893 | Eccentricity of the Sextant by Frederic Furbish, 1893, Page 42

35
The Vernier.
The vernier is a device for measuring the fractional part of a division of a scale or graduated arc
The vernier of the Pistor and Martins' sextant is a silver plate set in the index arm having the same radius of curvature as the graduated arc along which it moves.
In all verniers the space between the extreme graduations corresponds to a certain definite number of divisions of the arc or scale. Generally this number is one more or one less than the number of divisions in the same space on the vernier. Consequently verniers are divided into two classes
(1) Those in which the number of divisions on the vernier is one less than the number in the same space on the arc.

35
The Vernier.
The vernier is a device for measuring the fractional part of a division of a scale or graduated arc
The vernier of the Pistor and Martins' sextant is a silver plate set in the index arm having the same radius of curvature as the graduated arc along which it moves.
In all verniers the space between the extreme graduations corresponds to a certain definite number of divisions of the arc or scale. Generally this number is one more or one less than the number of divisions in the same space on the vernier. Consequently verniers are divided into two classes
(1) Those in which the number of divisions on the vernier is one less than the number in the same space on the arc.