Abstracts of Recent Technical Papers from Bell System Sources (01 April 1926)

A.I.E.E. Journal, Vol. 45, pp. 109-115, Feb., 1926. A.I.E.E. Journal, Vol. 45, pp. 243-253, Mar., 1926. ^ Astrophysical Journal, Vol. 52, pp. 309-319, Dec., 1925. 385 1 386 BELL SYSTEM TECHNICAL JOURNAL plane glass surface shows the normal and selective effects less well differentiated than for the similar coatings which form on metal plates. A rubidium film formed on the inside of a glass cylinder is found to exhibit, in the dark, a pure ohmic resistance. 

This decreases under illumination in a manner which appears to be explained as due to the liberation of photo-electrons which under a potential gradient form an added current along the tube. The Influence of Temperature on the Photo-Electric Effect of the Alkali Metals.4 HERBERT E. IVES and A. L. JOINSRUD. Special cells having a hollow central cathode were immersed in liquid air for an extended period to insure that any gases, if present, were condensed on the outer alkali metal coated walls. 

The temperature of the cathode was controlled by a stream of evaporating liquid air, whereby all temperatures between + 20 and --180° C. could be attained and held constant and be measured. In these cells the variation of photoelectric current with temperature in sodium, potassium, and rubidium is continuous, without abrupt changes. The effect is relatively small for sodium, showing hardly at all for blue light or white light, but clearly for yellow light. The behavior of rubidium is similar to that previously reported for potassium.