A major upgrade of an existing Mossbauer spectrometer is performed. Electronics are updated and a controlled atmosphere, variable-temperature cell with in situ reaction capability is fabricated; the cell is designed to be placed between the poles of a 5-inch electromagnet to provide a magnetic field up to 11 kilogauss. It is thought that this is the most versatile Mossbauer facility in the U. S. The equipment will be used for several studies in catalysis and coal chemistry including studies of electronic, magnetic, and lattice properties of supported metal clusters; active phases of cobalt and iron catalysts during hydrogenation of carbon monoxide; surface and bulk characteristics of zeolites exchanged with iron or cobalt, and their correlation with activity for decomposition of nitric oxide; transformations of iron minerals during coal devolatilization, char oxidation, and the deposition of mineral matter on boiler surfaces; and iron compounds in fly ash.