14 W.S. Sullivant and T. G.Wormley on Nobert's Test Plate. 
a Ye ene | 
| 1 | 0001000 | sr435 20 0000167 | srdrs | 
pets 0:000550 | sadrr || 25 0000143 | rater | 
Es . | ct URE RS ae 0000125 | gydrz 
0200 | ser 
of the English inch found by multiplying the decimals in the — 
8815. if 
2d and 5th columns by ‘08881 
Analysis of Nobert’s Test Plate of 30 Bands. 
i f 
— aan ‘saan Baal h tok eee. rogue’ Boalieh j fle 
1 7 ti ti6 16 30 ordre 
: 8 13,062 17 31 5eb23 
4 10 seb 19 33 xecee 
5 12 a 20 34 1 
6 13 net a 21 36 iis 
7 15 sidux 22 37 rides 
; = bic 23 38 za,teo 
24 40 ; 
B78 T2236 
10 23 cutee 25 41 
a wa 15,063 26 42 78,105 
12 25 cedex 27 43 ee 
13 26 sudo 28 442 ry 
14 28 sz.é10 29 wcdor 
15 29 334 30 
The figures in the 3d and 6th columns, showing the distance 
ce of the lines in each band, are the mean of numerous and 
ightly variant trials, particularly on the higher bands. Up to the 
26th band there was No serious difficulty. in resolvin 
i 
a 
Ty 4 
~~ Par. line. } Eng in. Band. Par. line. ~) Eng. in, aay 
We add the 3d and 6th columns, giving the distances in parts 4 
ones;*spectra se that is, lines each sie aes of two or more — 
separa into the sees ones on the whole of the 26h, 
ca mtn cece incr Bl eet 
or spurious li 
power, to run into each other readily 
e shown by a ess objective on the low tone 8 Hence the mere exhibition lines 
is not always conclusive evidence of their ultimate ac A A practiced eye will 
generally drstinguish the false from the true. Recourse to a higher objective often 
accomp) the same; but When fail, the micrometer only, toget 
a previous knowledge of the actual a of oe on lines, can determine whether 
the lines exhibited are real or spurious sy vse bac Gace 
bands on this plate aaa and beat striped with lines 
the true ones hea with the 1, cn the ga 
