Note 26 — Chapter VI
Reading edition
In the case of the paraffin prism the refracting angle (i) was 60°, and the deviation of the ray (d) was 50°. Hence, by the known optical formula for the index of refraction (r), we have—
r = sin i + d/2 / sin i/2 = sin 55°/sin 30° = 1·64
For the ice prism the refracting angle was 50°, and the deviation 50°; accordingly for ice we have—
r = sin 50 + 50/2 / sin 50/2 = sin 50°/sin 25° = 1·88
See “Cantor Lectures,” Society of Arts, December 17, 1900. J. A Fleming on “Electric Oscillations and Electric Waves.”