Conditions of sensibility of photo-electric cells with alkali metals and hydrogen . er mm. deflection for 3 metersscale distance. The anode of the cell was connected to the earththrough the galvanometer and a megohm resistance. The cathode of thecell was connected to a variable point in a water rheostat which isin series v/i th about 840 volts from a storage battery. The voltageay-plied to cathode could be ?aried by means o^ the water rheostat andit was measured by a Kelvin electrostatic voltmeter reading 0-600?^olts. The variation o^ the area o^ the metal illuminated was obtainedby varying th
Conditions of sensibility of photo-electric cells with alkali metals and hydrogen . er mm. deflection for 3 metersscale distance. The anode of the cell was connected to the earththrough the galvanometer and a megohm resistance. The cathode of thecell was connected to a variable point in a water rheostat which isin series v/i th about 840 volts from a storage battery. The voltageay-plied to cathode could be ?aried by means o^ the water rheostat andit was measured by a Kelvin electrostatic voltmeter reading 0-600?^olts. The variation o^ the area o^ the metal illuminated was obtainedby varying the opening o^ the iris diaphram A, which is placed at thelower end of a brass tube. This tube was blackened on the inside toprevent reflection of light. The intensity of illumination was varied by changing the posi-tion of the source of light L on the guide. The source of light wasa 4 candle power, 110 volt incandescent lamp, the entire bulb ofwhich was frosted. The candle power 0^ hhe lamp after frosting at 107 volts. The current was supplied by a 110 volt storage 14. Fin. 5. 15 Py mv-)^^ino; th= lamp or. the guide the intensity of illumination onthe metal in the pho lo-elec trio cell could be ^railed, and this varia-tion calculated directly by means of the inverse square law. Method. Hince the moat 8-=n3itive conUtions for the photo-electric effectare being sought, it is necessary to study the effect due to varyingall the poasible conditions in order to find the most effective set ofconditions. The variables in this work are the following:- P the pressure of the gas, D the distance between the electrodes, V the poten-tial difference applied to electrodes, A the area of metal illuminatedL the intensity of illumination, t the temperature o^ the cell, and dthe galvanometer deflection which is proportional to the current. Two sets of readings are possible for each cell, namely:- beforeforming and after forming the hydride surface. In this paper thisprocess will be called f
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecttheses, bookyear1912
