We request GEM beamtime to study the structure of a series of calcium germanate glasses. The changes in coordination number and properties which occur in alkali germanate glasses are well studied and now appear to be well understood. There is evidence, however, that these changes behave differently in alkaline earth (AE) germanate glasses. This may be because the higher charge on AE cations makes it possible to balance higher concentrations of negative charge, and this may affect the germanium coordination number. Thus the study of AE germanates will allow us to extend and develop models of the coordination number changes which occur in germanate glasses in general. Calcium is the best suited of the AE elements for this study, and its environment in glass is also of interest in itself. This study will also be of use in interpreting our previous results on lead germanate glasses.