128 A. A. Michelson—The relative motion of the Earth, etc. 
or dividing by 20X12 to obtain the means in terms of the 
distance between the fringes, 
N. N.E. E. S.E. : S.W. ; ; 
0-131 O-131 0108 0°102 0:096 0-086 0-075 0-046 
If a is the number of the column counting from the right 
and y the corresponding footing, then the method of least 
squares gives as the equation of the straight line which passes 
nearest the points x, y— 
y = 9°25x + 645 
If, now, we construct a curve with ordinates equal to the 
difference of the values of 4 y found from the equation, and the 
actual value of y, it will Pca the displacements observed, 
freed from the error in ques 
These ordinates are: 
N. N.E. E. §.E. Ss. S.W. W. N.W. 
—'002 —'O11 +°003 — ‘001 — 004 — 003 —001 +°018 
N. —*002 BE. +7003 N.E. —'011 N.W. +:°018 
Ss. — "004 W. —'001 5.W. —°003 8.E. —-001 
Mean= —-003 +°001 Mean= —:°007 +008 
+°001 +°008 
Excess= —'004 Excess=— ‘015 
The small displacements —0°004 and —0°015 are simply errors 
of experiment. 
The results obtained are, acter more strikingly shown 
by constructing the actual curve together with the curve that 
should have been found if the theory had been correct. This 
is shown i in fig. +. 
Or 
The dotted curve is drawn on the supposition that the dis- 
placement to be expected is one-tenth of the mistante bein 
the fringes, but if this displacement were only +45, t roken 
line would age hae more nearly with ey Pilot line 
than with the ¢ 
e Sritenisell tof of these results is oof there is no dis- 
pee of the interference ban result of the 
ypothesis of a stationary ether is ins shown si be incorrect, 
and the necessary conclusion follows that the hypothesis 1s 
erroneous. 
This conclusion directly peepee the explanation of the 
phenomenon of aberration which has been hitherto generally 
-aceepted, and which presupposes ry the earth moves through 
the ether, the latter remaining at rest. 
