The mechanism of gas evolution from mica used for vacuum tube was studied. Experiments suggested that there are two sources of gas evolution: one is the surface contamination and the other is (OH)-, constituent of crystal network. The temperature at which mica becomes opaque was between 720°C_??_750°C and dehydration began to take place at lower temperatures. Experi-ments on the gas evolution from mica stripped off mechanically and thermally in vacuum showed that there was no fundamental relation between the opaque temperature and dehydration reaction. The evolution velocity of H2O from mica seems to increase in appearance at the temperature at which it becomes opaque since its exposed surface area becomes larger by thermal peeling off of crystal layer.
R. S. Mackay performed an experiment which is not only singular but also has theoretical and practical importance. An ordinary incandecent lamp connected to A. C. line in series with an iron-cored choke and a condenser flashes intermittently of its own accord. The performance was analysed under suitable assumptions and approximations. The results are qualitatively in geod agreement with the experiment.
A vacuum furnace using a molybdenum heater for use in pulling single crystals of germanium from a melt is described. It has a pulling rod with rotation, two removable impurity adders and an adjusting rod for crucible bdse and coufd be observed during the run through windows with shutters. The vacuum system consisted of a 4'' oil diffusion pump of the speed of 100l/sec and a 500 l/min mechanical pump and the vacuum higher than 5×10-5 mmHg was maintained during operation.
Spectrophotometric curves of Lippman photographs were measured and asymmetric curves-were obtained (Fig. 1 and Fig. 2). These curves agreed very well with the result of calculation for alternating layers on the image basis (Fig. 5). The calculation could be performed by applying a theory of chain of four terminal networks to multiple thin layers of periodic structure.
An ordinary electro cardiograph is an electromagnetic oscillograph type and is inconvenent for diagnosis and study of varying phenomena. Therefore, the authors made a cathode-ray oscillograph with a long persistence phosphoresic brown tube. It had a repeatable single sweep circuit which repeated its sweep by a trigger pulse produced from R spine of the cardiac action current, and pulse made it possible to overlap the 2n'th (n=0_??_4) R spine upon the first R spine. Spines could be counted and selected by an electric sealer of 16.
Structure of thin oriented films of silver of thicknesses from 20 to 300 Å, produced by con-densation on cleaved surfaces of single crystals of NaCI, was examined by means of electron-microscopy and diffraction. When examined by an electron microscope, the general feature of the films was similar to that of the non-oriented. However, characteristic images due to definite orientation of crystallites in the films were also found, such as streaks parallel to Ag-direc-tion, the extinction contours (Fig. 3), and the rectangular holes appearing in some films when corroded with aqueous solution of NaCI. The structure were clearly shown to be affected by the amount of residual gas during con-densation of silver in evaporating apparatus. A possible explanation for the result is proposed.