548 Intelligence and Miscellaneous Articles. 



(2) If the magnetic lines of force are at right angles to the lon- 

 gitudinal direction of the wire projecting into the field, the tractive 

 force at right angles to the lines of force is smaller in iron than 

 the force p #. The ratio p jt/p I (where p% and p J_ are the tractive 

 forces parallel and at right angles to the lines of force respectively), 

 which with mean strengths (about H=100) is greater than 100, 

 rapidly decreases as the field increases and appears to approach 

 unity. — Wiedemann's Annalen, No. 1, 1895. 



ON THE INFLUENCE OF MAGNETIZATION ON THE CONSTANTS OF 

 ELASTICITY IN IRON. BY A. BOCK. 



The result of this research is stated as follows by the author : — 

 By magnetization the constants of elasticity of soft iron, the 

 modulus of torsion, and the modulus of elasticity are certainly 

 not altered by more than \ per cent. The series of observations 

 indicate that the flexure diminishes, at the same time the torsion' 

 seems also to diminish, while the ratio of the lateral contraction 

 to the longitudinal expansion increases. Iron is more incom- 

 pressible in the magnetic field. Nothing can be alleged with 

 certainty as to magnetized steel bars. These results are in perfect 

 agreement with the well-known investigations of Gr. Wiedemann, 

 and they may be deduced from the theory propounded by that 

 author on the assumption of rotating molecular magnets. — Wiede- 

 mann's Annalen, No. 3, 1895. 



ON THE MAGNETIZATION OF IRON BY VERY SMALL FORCES. 

 BY WERNER SCHMIDT. 

 The experimental results of this research are given by the author 

 in the following statements : — 



1. Steel follows small magnetizing forces more rapidly than iron. 



2. The magnetization function k of mild steel is greater for small 

 forces than that of iron. In the present case k (steel) is to k 

 (iron) as 4 is to 3. The stronger magnetization ordinarily ob- 

 served in iron is only met with in greater magnetizing forces, for 

 instance, H>1. 



3. The constancy of the magnetizing function k for very small 

 forces, first observed by Lord Eayleigh, is confirmed. The 

 boundary of proportionality between magnetizing forces and mag- 

 netic moments may be taken with sufficient accuracy for technical 

 purposes as near the magnetizing force H x =0*06. This value 

 represents a rather sudden transition in the curve K=f(K l ). 

 Below this the deviations from proportionality are only very feeble, 

 that is the curve K=f(K 1 ) passes into a parallel to the H-axis. 

 The point at which it can be identified with a straight line 

 (parallel) is different according to the nature of the iron investi- 

 gated, and especially according to the sensitiveness of the 

 apparatus used for the measurements, without varying much from a 

 certain mean value which may be regarded as lying between the 

 magnetizing forces 1^ = 0*03 and 0-04. — Wiedemann's Annalen, 

 No. 4, 1895. 



