Abstracts of Technical Articles from Bell System Sources (01 January 1938)

Jour, of Applied. Physics, September 1937. R. M. A. Engineer, November 1937. Phys. Rev., November 1, 1937. 184 ABSTRACTS OF TECHNICAL ARTICLES 185 spots made up of three distinct patterns which are displaced with respect to each other and with respect to the primary beam position. Polycrystalline surfaces made up of rather large crystals produce patterns of spots which are often drawn out into streaks lying approximately parallel to the plane of incidence. This effect, which is attributable to refraction and is a proof of smoothness of the surface, is most pronounced after etching in nitric acid. It is rarely, or never, found after etching in a mixture of hydrogen peroxide and ammonium hydroxide. Nitric acid etch produces upon the surface of a single crystal of cuprous oxide, or upon a polycrystalline surface made up of rather large crystals, crystals of some new compound which are cubic with cell edge 8.35A. 

These are sharply oriented with one or another of the most important planes parallel to the gross surface plane of the oxide. The sharpness of this orientation is proof of the flatness of the underlying oxide surface upon which the crystals are formed. This new 8.35A structure is produced by potassium cyanide etch as well as nitric acid, but never by sulphuric acid nor by ammonium hydroxide. On the Ionization of the F2 Region.4 W . M . GOOD ALL. In this paper, the available d a t a on F 2 region ionization for Peru, Australia, and this country are analyzed in a way that permits the separation of effects due to variations in solar ionizing force from effects due to seasonal and annual changes.