Correction charts for Lorentz and polarization factors in anti‐equi‐inclination photographs

indices, different from the simple shear p l a n e { l l 2 } which might be expected on the basis of the Burgers 's mechanism. This, then, is in agreement with the results found for m a n y t ransformations of 'martensi t ic ' type (cf., for example, Table 2 given in a review by Cohen (1951)). In addit ion, our results for zirconium leave open the possibility of a plane {569}, which is nearer to {112} than to {144}, as found by Bowles for l i thium. Wi th regard to the physical meaning of habi t planes with complicated indices we refer to a recent paper by Machlin & Cohen (1951) in which other recent considerations of this problem are discussed.