THE NEW NATIONAL STAND AED OE LENGTH, AND ITS PEINCJPAL COPIES. 071 
Bars compared with 
Bronze 28. 
Position of Bar 
Inside or Outside. 
Number of 
sets of 
observations. 
Excess of Bar 
above Bronze 28 
increased by 
HOOOO. 
Proljable Error 
of one set. 
Probable Error 
of Mean. 
Bronze 1 
Inside. 
4 
r. 
1*0236 
r. 
0*004406 
r. 
0-00220;i 
Bronze 1 
Outside. 
4 
1*0180 
0*004088 
0*002044 
Bronze 2 
Inside. 
12 
0*9986 
0*004292 
0*001239 
Bronze 2 
Outside. 
12 
0*9935 
0*004367 
0*001261 
Bronze 7 
Itiside. 
12 
1*0001 
0*003359 
0*000970 
Bronze 7 
Outside. 
12 
0*9977 
0*003307 
0*000955 
Bronze 11 
Inside. 
8 
1*0219 
0*008207 
0*002902 
Bronze 11 
Outside. 
8 
1*0172 
0*003534 
0*001336 
Bronze 12 
Inside. 
16 
1*0137 
0*003807 
0*000952 
Bronze 12 
Outside. 
16 
1*0128 
0*004123 
0*001031 
Bronze (reversed)... 
Outside. 
16 
1*0250 
0*003929 
0*000982 
Bronze 15 
Inside. 
27 
0*9737 
0*004888 
0*000978 
Bronze 15 
Outside. 
18 
0*9678 
0*004795 
0*001130 
Bronze 20 
Inside. 
12 
1*0105 
0*003013 
0*000870 
Bronze 20 
Outside. 
12 
1*0040 
0*004775 
0*001378 
Remarking that the probable error will be the same for the Mean Excess aho^e 
Bronze 28 and for the Increase of Excess depending upon the Compared Bar being- 
inside, the results from these observations are the following : — 
Name of Bar. 
Mean Excess above 
Bronze 28. 
Increase of Excess 
when compared Bar 
is Inside. 
Probable Error. 
r. 
r. 
r. 
Bronze 1 
1*0208 
+ 0*0028 
0*00150 
Bronze 2 
0*9960 
+ 0*0025 
0*00088 
Bronze 7 
0*9989 
+ 0*0012 
0*00068 
Bronze 11 
1*0195 
+ 0*0023 
0*00160 
Bronze 12 
1*0132 
+ 0*0004 
0*00070 
Bronze 15 
0*9708 
+ 0*0030 
0*00075 
Bronze 20 
1*0072 
+ 0*0032 
0*00081 
These results undoubtedly support the idea that the bar appears too long when in the 
Inside position by a quantity not differing much from 0’'-0022=:0'"’000008. 
Much time was employed, in the latter- part of 1851 and the beginning of 1852, in 
the observations of numerous bars, the results of which will be given hereafter. In 
many of these observations Mr. W. Simms, jun. took a part, and thus there was frequent 
comparison of the results given by two different observers. In the autumn of 1852, the 
feeling of insecurity, with regard to personal equation and the influence of the bar’s 
position, pressed so strongly on Mr. Sheepshanks, that, after consulting with me, he 
determined on making an extensive series of observations with the assistance of several 
obsen’ers who were familiar with micrometrical observations, and whose accuracy could 
not be questioned. The persons who thus aided Mr. Sheepshanks were, Mr. Hendek- 
SON and Mr. Dunkin of the Royal Observatory, Mr. Simms, Mr. W. Simms, jun., and 
Mr. Waeeen De la Rue. The following Table gives the immediate results of the 
operation. The element exhibited is the apparent excess of each bar above Bronze 28, 
4 s 2 
