INTRODUCTION We present here an inventory of the academic physics establishments main tained in the scientifically advanced countries at the turn of the century. Althoughmost of the results are expressed quantitatively neither subject nor sources permit precision: the reader should constantly keep in mind the approximate character and devious construction of the figures in our tables. These figures, though approximate, can nonetheless be useful, not onlyto historians concerned with physics circa 1900, but to anyone seek ing a benchmark against whichthe state and growth of physics in other eras can be measured. We do not here address the ultimate questions of the causes of growth (or retrenchment) of physics establishments, or the role of material factors in national scientific styles and achievements. But we are persuaded that historical generalizations and international compari sons brought forward in …