Geokinetics retort number 21 was constructed on June 27, 1979. The test data, consisting of motion measurements from both high speed movie film and post test survey contour maps and accelerometer, time of arrival, and SLIFER measurements have been compiled, evaluated and interpreted. These data have then been put into the format which will be useful in comparison with analytical results from a structural analysis model in a similar manner to the retort 18 data given in reference 1. This memo discusses both optical and electronic data from retort number 21 and includes some comments concerning the general ground motion behavior.