Chapter 19 of 41
Measurement of the Distance between the Mirrors.
Experimental Determination of the Velocity of Light Made at the U.S. Naval Academy, Annapolis · Albert A. (Albert Abraham) Michelson
Square lead weights were placed along the line, and measurements taken from the forward side of one to forward side of the next. The tape rested on the ground (which was very nearly level), and was stretched by a constant force of 10 pounds.
The correction for length of the tape (100.006) was +0.12 of a foot.
To correct for the stretch of the tape, the latter was stretched with a force of 15 pounds, and the stretch at intervals of 20 feet measured by a millimeter scale.
The following are the values obtained from five separate measurements of the distance between the caps of the piers supporting the revolving mirror and the distant reflector; allowance made in each case for effect of temperature: