III. The effect of pressure upon are spectra.―No. 1. Iron

Abstract

As this paper is the first record of work undertaken with the large Rowland Grating in the Physical Laboratory of the University of Manchester, the occasion seems a fitting one for the description of the mounting of the instrument, which differs in several essential features from previously described systems. A detailed account of the scheme adopted for the adjustment of the apparatus is also given in the hope that it will be of service to those who may be confronted with a similar task. The papers of Ames and Kayser on the adjustment of their own systems of mounting have been consulted and detailed acknowledgment will be found in the text.