326 R. W. G. WycJcoff— Crystal Structures of 



Table II. 



Data for preparing ruler when distance from crystal to plate 



is 4 cm. 



Left side Right side Left side Right side 



of ruler of ruler of ruler of ruler 



cm. cm cm. cm. 



1.20 



34.06 



3.10 



14.61 



1.25 



32.77 



3.20 



14.25 



1.30 



31.57 



3.30 



13.92 



1.35 



30.45 



3.40 



13.60 



1.40 



29.42 



3.50 



13.31 



1.45 



28.45 



3.60 



13.03 



1.50 



27.58 



3.70 



12.77 



1.55 



26.74 



3.80 



12.52 



1.60 



25.96 



3.90 



12.29 



1.65 



25.23 



4.00 



12.07 



1.70 



24.55 



4.10 



11.86 



1.75 



23.90 



4.20 



11.67 



1.80 



23.29 



4.30 



11.48 



1.85 



22.73 



4.40 



11.30 



1.90 



22.19 



4.50 



11.13 



1.95 



21.67 



4.60 



10.97 



2.00 



21.18 



4.70 



10.82 



2.05 



20.72 



4.80 



10.68 



2.10 



20.28 



4.90 



10.54 



2.15 



19.86 



5.00 



10.40 



2.20 



19.47 



5.10 



10.28 



2.25 



19.09 



5.20 



10.15 



2.30 



18.72 



5.30 



10.04 



2.35 



18.38 



5.40 



9.93 



2.40 



18.05 



5.50 



9.82 



2.45 



17.74 



5.60 



9.71 



2.50 



17.44 



5.70 



9.62 



2.55 



17.14 



5.80 



9.52 



2.60 



16.87 



5.90 



9.43 



2.65 



16.60 



6.00 



9.34 



2.70 



16.35 



6.10 



9.26 



2.75 



16.10 



6.20 



9.18 



2.80 



15.86 



6.30 



9.10 



2.85 



15.63 



6.40 



9.02 



2.90 



15.42 



6.50 



8.95 



2.95 



15.20 



6.60 



8.88 



3.00 



15.00 



6.70 



8.81 







6.80 



8.74 







6.90 



8.68 







7.00 



8.61 



