Anderwn and Lean. 



Roy. Soc. Proc., vol. 72, Pldte 15. 



Al. 65%. Annealed e* water- 

 etched for i2^t hours, x 19. 



N2. 

 AL 51-6%. Cast, x ia Oblique Ilium 



. 



A1.5i-8%.Annealed.xi9.0bliqueIllum. Al.15-42%. Cast. Annealing- Exp 



Oblique Ilium, x 13. 



N5. 



ALi5-42%.Annealed at30oC. 

 Oblicrue Ilium. xi9. 



Al.42-5%. Annealed, x 270 

 Nachet Prism . 



