Phil. Mag. Ser. 6, Vol. 33, PLY. 



Fig. 6. 



Area at X, fig. 5 (x'fi diameters), to show bui 



Fig. 7. 



Area at Y, fig. 5 (X 6 diameters). The lower 

 edge of the fracture is guided round the 

 drilled aperture by the burr. 



Fig. 



Finished cell for a Rayleigh Interference Refractometer. 



Fig. 9. 



Polarimeter Tube. 



Fig. 10. 



End of Polarimeter Tub^, by reflected light only 

 (X 6 diameters). Shows detail of joining. 



