Experimental gƒ-VALUES for Seventy Elements.

Relative intensities of 39000 spectral lines with wavelengths between 2000 and 9000 A have been determined on a uniform energy scale for seventy elements. The light-source was an arc between copper electrodes to which a single element was added in the ratio of 1 atom of element to 1000 atoms of copper. The spectrograms were calibrated with standard lamps. The temperature of the arc was determined, by comparison of the observed intensities with published relative gf-values, to be 51000 + 1100 K. The degree of ionization of eleven elements in the arc was determined by comparison of intensities in spectra of neutral and ionized atoms with known absolute gJ-values. With the aid of Saha's ionization equation, the electron density in the arc was found to be 2 4 X 1014 . The ionization of seventy elements separately added to the arc was then calculated with Saha's equation. A correction was made for diffusion of atoms from the arc stream. With this information, relative values of gf on a uniform scale can be computed for the 25000 lines which have been classified. By calibration with known absolute gJ-values, the scale is put on an absolute basis. The accuracy of the results is discussed. A curve of growth for V ii in the sun is constructed with our gf-values to test their utility.