The 1.5-meter Cassegrain spectrograph is an ultraviolet transmitting grating spectrograph which is used at the f/7.5 focus where the scale is 18.1 arcseconds/mm. It is identical to the 2.1-meter telescope White Cassegrain spectrograph at Kitt Peak National Observatory and therefore allows one to obtain similar spectrograms in both hemispheres. The ARCON-IRAF software which is used to configure and readout the CCD detector is separately documented (see: The ARCON-IRAF Interface: Spectroscopy with the 4.0-m R-C Spectrograph. A Preliminary User's Guide). A version of an ARCON manual specifically for the 1.5-meter Cassegrain spectrograph is under development.