The authors make no attempt to summarize the results available in this area through approximate solutions of various kinds to the 3-D field equations. Nor do they present, for readers prepared to utilize modern computer techniques, finite element, boundary integral, and other numerical techniques for obtaining such solutions. Finally, it seems to the reviewer that there is little added to this book by an "Introductory Chapter" of approximately 40 pages, authored by Sih, on the "strain-energy-density factor" theory of crack growth and its extension to 3-D problems. First, the chapter seems extraneous in the sense that nothing else in the book touches on theories of crack growth. But this theory, while presented with evident enthusiasm, seems to derive from no self-consistent or physically plausible description of the crack growth process. Instead, failure is assumed to occur when a local minimum value of the energy density, at some given radius from the crack tip, reaches a critical value. Why the energy density, and especially, a local minimum of it, should be chosen is unclear enough. But the function does indeed have a local minimum, in general, and it seems disconcerting to take as critical a value of the energy density for which both greater and lesser values occur at other points at the same given radius from the crack tip.

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The potential of a semiconductor slab in a magnetic field satisfies LAPLACE'S equation AV = 0. The magnetic field causes a special boundary condition at the free boundaries. It is shown how this boundary value problem is solved by means of a resistance-network and feeding currents. For obtaining stability of the iterative process the feeding currents have to be calculated by a special method.

Le total des marchandises transporters jusqu'a present de l'Amerique du Nord, par les navires du Comity international de la Croix-Rouge, s'eleve a 10.125 tonnes. 3. Ligne Atlantique-Sud. Le navire a, moteur su^dois «Finn», affr£t6 pour la duree de la guerre, est arrive le 2 aout a Marseille, venant de Buenos Aires ; il d^chargera dans ce port une cargaison de 2.445 tonnes de marchandises, qui sera immediatement re"achemin6e sur la Suisse. Le «Finn » sera ensuite dirige sur Lisbonne, d'ou il transportera a Marseille une partie des secours qui s'accumulent dans ce port. Grace a l'appui de l'Office de guerre suisse pour les transports, les navires suisses « Chasseral», «St-Gothard», «Saentis», « St-Cergue » et « Eiger » ont transports de Janvier 1941 a. fin avril 1943, en huit voyages, 1.971 tonnes me'triques de secours de Buenos Aires-Santos-Rio a destination de G6nes.