By William R. Hamilton

A extract from a letter by Hamilton,

appeared in theRemarques de M. Hamilton, Directeur de l'Observatoire de Dublin, sur un Mémoire de M. Plana inséré dans le Tome VII de la Correspondance Math. (Extrait d'une Lettre).

This letter is available in the following formats:

In this letter, Hamilton responds to an assertion of Plana, of Turin, disputing the theorem that light rays, in an isotropic medium, that undergo successive reflections are orthogonal to a series of surfaces. Hamilton explains how this theorem could be deduced from Plana's analysis, and outlines how the validity of this theorem follows from his own approach to the study of optics.

Links:

D.R. Wilkins(

School of Mathematics

Trinity College, Dublin