At the time of Mr. Brödel's death, two of the series of three drawings had been completed. The third was in the stage of preliminary sketches based on his research studies to that date. P.D. Malone has completed the research and has executed the third drawing, and the labelled outline sketch. The two non-artist authors (S. R.G. and S.J.C.) provided the material and otherwise assisted Mr. Brödel. cf. p. -.