The previous work was omitted on account of various inaccuracies and want
of practice, which made the separate results differ widely from each
other.




The Formulæ.



The formulæ employed are--

d′
(1) tan φ = -----
r

2592000″ × D × n
(2) V = -----------------
φ″

φ = angle of deflection.
d′ = corrected displacement (linear).
r = radius of measurement.
D = twice the distance between the mirrors.
n = number of revolutions per second.
α = inclination of plane of rotation
d = deflection as read from micrometer.
B = number of beats per second between electric Vt₂ fork and
standard Vt₃