220 Permanence of the Butherfurd Photographic Plates. 

 Results of the Measures, Plate 18, Y-co6rdinate {Continued). 



Desig. 



of 

 Star. 



Microm. Readings. 



Diflf. 



Mean 

 2 



Screw 



and Div. 



Error. 



Final 

 Reading. 



Obs'r. 



On 

 Star. 



On scale. 



Line 



Reading. 



A28,E 

 W 



16 E 

 W 



A30,E 

 W 



n E 



W 



A39,E 

 W 



18 E 

 W 



9.0440 

 9-5310 

 8.9845 

 9-5035 



9-0245 

 9-5115 

 8-9715 

 9-5115 



9-0295 

 9.5160 

 9.0205 

 9-4955 



115 

 115 

 115 

 115 



83 

 83 

 83 



83 



41 

 41 

 41 

 41 



9.2225 

 9.6870 



9-1745 

 9.6600 



9-4595 

 9-9215 

 9 4080 



9-9355 



10.0925 



10.5525 

 10.0905 



10.5515 



+0.1785 

 +0.1560 

 +0. 1900 

 +0.1565 



+0.4350 

 +0.4100 



+0.4365 

 +0.4240 



+ 1.0630 



+1-0365 

 + 1.0700 

 + I-0560 



0.0836 

 0.0866 



0.2II2 

 O.215I 



0.5249 

 0-5315 



+.0008 

 +.0008 



+.0035 

 +-0035 



— .0004 

 — .0004 



115.0844 

 115.0874 



83.2147 

 83.2186 



41-5245 

 4I-5311 



D. 



J. 



D. 

 J. 



D. 

 J. 



