Experiments for determining the Length of the Pendulum. 365 
TABLE contin ued. 
The Pieces changed. 
| 698-0 eS 956-91 
| 
June 65°5 HE2:7. 
10th. | 64-0 112-5 696-0 955'76 
61-0 106-2 | 693-2 957'61 
64:5 | 108-0 693°5 955-26 
65-0 106-2 694-5 956-91 
67-2 GR Ie a FA ANS ck 107-0 | 696-0 
Mean of the whole 
956-91 
————~"Vfean of the whole | 956-47 
Hence the distance between the knife edges is 39:4 inches 
+956:47 divisions of the micrometer. 
June 12th, the knife edges having been adjusted parallel to 
each other, the following measurements were taken, the knife 
edges being viewed as dark objects on a white ground. 
Dark on a White Ground. 
Readings of the Micrometer. 
Date. |Near side of|Further side Divisions 
the bar. | of the bar. Mean. | Scale. | + 39-4 in, 
June 50-0 50-0 50-00 | 10065 | 956-50 
12 50-0 50-0 50-00 =e 956-50 
50-0 50-0 50-00 whe 956-50 
49-0 50-0 49-50 Ls 956°50 
12 465 |. 440 42:25 | 1001-0 | 955-75 
44-5 44-5 45°50 | 1001-0 | 95550 
42-0 43-0 42:50 | 1003-0 | 960-50 
43-0 | 43-0 43:00 | 1003-0 | 960-00 
13 375 | | 38°0 37°75 994-0 | 956-25 
350 | 39-0 37-00 993-5 | 956-50 
38-0 35-0 3650 | 1001-0 | 964-50 
38-0 38-0 38:00 | — 963-00 
"4 |. 25:5. | 275 26:50 | 987-0 | 960-50 
25-0 26:5 25:75 | 987-5 | 961-75 
240 25-2 24-60 = 962-90 
25-0 25-7 25-25 BS 962-25 
14 \ 795 78:0 | 7875 | 10420 | 963-25 
76:0 75-0 “75°50 2s 966-50 
72:0 71:5 71:75 1035°2 963°45 
74-0 73-5 73°75 — | 961-45 
Mean of the whole 960-00 
Correction for irradiation | —5'51 
(see page 179) 954-49 
By the foregoing measurements, the distance hetween the knife 
edges appears to be 39-4 inches +954" 49 divisions. 
The 
