Honorable Secretary of the Navy, and referred by him to this Office. At
the suggestion of the writer, the paper was reconstructed with a fuller
general discussion of the processes, and with the omission of some of the
details of individual experiments.

To prevent a possible confusion of this determination of the velocity of
light with another now in progress under official auspices, it may be
stated that the credit and responsibility for the present paper rests with
Master Michelson.

Simon Newcomb,
_Professor, U.S. Navy_,
_Superintendent Nautical Almanac_.

Nautical Almanac Office,
Bureau of Navigation,
Navy Department,
_Washington, February 20, 1880._




Table Of Contents.



Introduction
Theory of the New Method
Arrangement and Description of Apparatus
Determination of the Constants