The function

which does

**References**

Fischer, G. (Ed.). Plate 122 in
*Mathematische Modelle/Mathematical Models, Bildband/Photograph Volume.* Braunschweig, Germany: Vieweg, p. 119, 1986.

Leitere, J. ``Functions.'' §7.1.2 in
*Mathematical Models from the Collections of Universities and Museums* (Ed. G. Fischer).
Braunschweig, Germany: Vieweg, pp. 70-71, 1986.

© 1996-9

1999-05-26