Intensity measurements in the helium spectrum

The absolute and relative intensities of thirteen lines of the helium spectrum, extending through the visible region, have been measured by a modification of the method developed by Ornstein and Dorgelo. The change of the method has consisted in comparing each line directly with the known emission from a tungsten filament, operated under constant conditions. The results for a discharge in a capillary tube, with pressures from 1.92 to 34.3 mm show that the absolute intensities increase rapidly to a maximum for pressures in the neighborhood of 2 to 4 mm, below which they tend toward zero. The relative intensities of the singlet system are favored by lowered pressures, and the higher members of the triplet system are likewise favored over the lower members, while the relative intensities within the singlet series show little effect of pressure

Accreditation of Public Schools

The problems of this thesis are three-fold: To familiarize administrators and citizens with the problems and needs of accreditation to the extent that these problems become axiomatic, To determine who does the accreditation and how comprehensively is it done, To revise the present state form used for accreditation of Kentucky schools by comparison with other state-accrediting forms

Effect of Change in Pressure and Current Density on the Spectrum of Helium

A study has been made of the intensities of the various lines of the neutral helium spectrum, with the particular view of obtaining regularities in the variation of the relative intensities with changes in current density and pressure. The method used is a modification of that developed by Ornstein at Utrecht. A study has been made of the lines 5876, 5016, 4713, 4472, 4387, 4143, 3964, 3889 and 3819, at pressure of 27,9 and 3 mm., and currents of 64, 20, and 4 milliamperes in a capillary discharge. The results show little variation with current density except for the trial at 3 mm pressure. At this pressure, the higher members of the series seem to be relatively stronger, and the singlet system is relatively stronger with a decrease in current density. There is a very definite shift of energy into the higher members of the various series with a decrease in pressure. There does not appear to be much change in relative intensity for the two higher pressures. The singlet system is made more prominent by decreasing the pressure. Tables are included showing the relative intensities of three members of the diffuse series of the triplet system, 2 members of the principal series of the singlet system and three members of the diffuse series of the singlet system.</p