The question of dependence of the measurable amount of sidereal aberration upon the thickness of glass or other transparent material in the telescope (a question which involves theoretically one of the most delicate points in the Undulatory Theory of Light) has letely been agitated on the Content with much earnestness. I have calculated the curvature of the lenses of crown and flint glass (the flint being exterior) for correcting the sperical and chromatic aberration in a telescope whose tube is filled with water, and have instructed Mr. Simms to proceed with the preparation of an instrumet carrying such a telescope. I have not finally decided whether to rely on zenith distance of γ Draconis or on right ascensions of Polaris.
I alluded in the last Report to a telescope whose tube should be filled with water for examination of the coefficient of siderieal aberration where the pencil of light passes through a considerable extent of refractory medium. I have decided to sue it in determining the apparent zenith deistance of γ Draconis at the proper seasions of the year.
But it is really a result of great physical importance, not only affecting the computation of the velocity of light, but also influencing the whole treatment of the Undulatory Theory of Light.
[…]
I think myself justified in concluding that the hopothesis of Professor Klinkerfues is untenable.