VELOCITY OF WHITE AND OF COLOURED LIGHT. 
261 
December 21, 1880, No. 8. 
Wheel. 
Clock. 
Reading. 
Differences. 
At mean reading. 
Reading. 
Alternate 
differences. 
Alternate second 
differences. 
7,785 
9,628 
13,277 
1,843 
1,825 
8,707 
11,453 
7,927 
17,479 
25,352 
34,756 
42,518 
51,729 
17,425 
17,277 
(17,166) 
16,973 
259 
304 
Signal at 10,263 
Signal at 30,460 
F=-001833 
7=33,972 
4/= 292 
7= -85830 
Correction for friction, &c. = -f ’00298 
v= -86128 
%=—=469'88 
V 
December 21, 1880, No. 9. 
Wheel. 
Clock. 
Reading. 
Differences. 
At mean reading. 
Reading. 
Alternate 
differences. 
Alternate second 
differences, 
5,630 
7,936 
12,525 
2,306 
2,295 
6,783 
10,231 
7,000 
15,737 
26,172 
34,790 
45,100 
53,566 
19,172 
(19,053) 
18,928 
18,776 
244 
277 
Signal at 8,924 
Signal at 29,096 
F=-002299 
7=25,295 
4/= 248 
v= -95270 
Correction for friction, &c. =— "00247 
v= -95023 
n— "7=413'32 
V 
r 
From Nos. 8 and 9 - 
l 
2m ^ + ^ PB =187,736 
r ’ 
1—4-=-999678 
g+p 
Product=V= 187,676 
' 
- Correction for second term = — 60. 
J 
