218 Permanence of the Ratherfurd Photographic Plates. 

 Results of the Measures, Plate 18, X-coordinate (^Continued). 



Desig. 



of 

 Star. 



Microm. Readings. 



Diff. 



Mean 

 2 



Screw 



and Div. 



Error. 



Final 

 Reading. 



Obs'r. 



On 



Star. 



On Scale. 



Line 



Reading. 



A28, E 

 W 



7 E 

 W 



A30, E 

 W 



8 E 

 W 



A39,E 

 W 



9 E 

 W 



9.0105 

 9.5070 

 8.9955 

 9.5070 



9.0150 

 9.5205 

 8.9825 



9.4875 



9.0260 

 9.5150 

 8.9955 

 9.4810 



49 

 50 

 49 

 50 



36 

 38 

 36 

 38 



18 



19 



18 



19 



10.7020 



11.4035 

 10.6910 



II. 4150 



10.9900 

 9.6840 



10.9650 

 9.6500 



9.1645 

 9.8215 



9-1505 

 9.8095 



+1-6915 

 + 1-8965 

 + 1-6955 

 + 1.9080 



+ 1- 9750 

 +0.1635 



+ 1.9825 

 +0.1625 



+0.1385 

 +0.3065 

 +0.1550 

 +0.3285 



0.8970 

 0.9009 



0.5346 

 0.5362 



0.1112 

 0.1209 



+.0005 

 +.0005 



+.0010 

 +.0010 



+.0002 

 +.0002 



50.3975 

 50.4014 



37.5356 

 37-5372 



18.6114 

 18.6211 



D. 

 J. 



D. 



J. 



D. 

 J. 



