NINE hundred scientific workers, including no fewer than 160 non-Germans, attended the second Zeiss-Kurs in Jena last month. As apparently only three Englishmen were present, it would appear to be worth recording that many German firms sent several representatives to this three-day course of twelve lectures, at which more than two hundred instruments were set out, to be demonstrated by between fifty and sixty experts. On one evening during the course, a performance was given in the Zeiss Planetarium. The first day was devoted to microscopy and metallography, the lecturers being Prof. Hanemann (speed of alloy transformations); Prof. Pomp (causes of failure in the working of iron and steel) ; Dr. Scheil (theory of hardening steel) and Dr. Hansen (light metals and their uses). The second day's lectures dealt with spectro-analysis and photometry, the lecturers being Prof. Gerlach (progress in spectro-analytical methods) ; Dr. Ginsberg (new photometrical methods in light metal analysis) ; Dr. Kamb (various spectro-analysis investigations for industrial laboratories) and Dr. Kaiser (contributions to the spectro-analysis of light metal alloys). The third day's work was on fine measuring, the lecturers being Prof. Kienzle (means of obtaining reliable dimensional data regarding machine components) ; Dipl.-Ing. Claassen (supervision of gear wheel manufacture) ; Dr. Berndt (testing of gear teeth) and Herr Nichterlein (modern developments in projection as a means of measuring).