THE K 1 - AND TRUE g-VALUES OF POLYCRYSTALLINE FE.RRITES

473

The t e m p e r a t u r e dependence o f . H ~ obtained b y us was such t h a t H ~ became zero at a temperature somewhat lower t h a n the Curietemperature of the material considered, as was to be expected.

J. SmzvXR Physical Laboratory RVO-TNO Vlakte van Waalsdorp The Hague, Netherlands. Received 20th May, 1957. REFERENCES I) Snieder, J. Appl. sci. Res. B 6 (1957) 301. 2) S-tandley, K. J. and K. W. H. Stevens, Prec. Phys. Soc. B 69 (1956) 993; D. M. S. Bagguley, Prec. Roy. Soc. A 228 (1955) 549. 3) Healy, D. W. Phys. Rev. 104 (1956) 634. 4) Healy, D. W. Phys. Rev. 86 (1952) 1009. 5) Galt, J. K. Prec. Instn Elect. Engrs 104 B (1957) 189.

ERRATA Reflection from a wire grid at arbitrary incidence Appli. Sci. Res. ]34 (1955) 393 by ). R. W a i t

I n eq. (25) cos 0 cos @o Z, d]~/o should be replaced b y cos @o 74 d]wo cos 0. R a d i a t i o n f r o m an electric, d i p o l e in the p r e s e n c e of a corrugated cylinder Appl. Sci. Res. B 6 (1957) 117 by J. R. W a i t In eq. (20) d should be replaced by Nd, and at ~:hemiddle of p. 122, W should read w = Nd/2

=

d/2

O n 1:he theory of'reflection f r o m a wire grid parallei to a n interface between h o m o g e n e o u s m e d i a Appl. Sci. Res. B 6 (1957) 259

b y J. R. W a i t I n eq. (23) m should be replaced b y m2 under the radical signs. Discussion

of a Wlener-Hopf t y p e i n t e g r o - d l f f e r e n t i a l equation

Appl. Sci Res. B 6 (1957) 312 by J. A. Sparenberg, T. C. B r a a k m a n and C. W . B e n t h e m In expression (3---II) the upper limit of the second integral should read

u ' instead of u,. I n the first line of (4---2) instead of (~u-s)# 89 read (a~u-s)~i. Received 29th July, 1957.