Wednesday, March 16, 2011

"White Bronze" Eagles of McLennan County

KWTX article from 9/2/2010
Today, the eagles perched atop the McLennan County Courthouse were unceremoniously removed.  The plan is to replace the eagles with replicas cast in aluminum.  Some time ago, a good friend of mine told me that the eagles were made of cast zinc and had red lights for eyes.  Distracted by the image of an eagle-of-justice watching my every move with its glowing red eyes, I ignored the curious fact that they were made of zinc.  Zinc... how strange.  In the 1850's, zinc became the commodity of choice for the cast sculpture... cheap cast sculpture.  Zinc ore was plentiful worldwide and thus cheap to obtain.  The melting point for zinc is low, 787.15 F, thus the facility and equipment needed to cast large sculptures was much less expensive than for bronze or cast-iron casting.  Cast-iron was relatively cheap as a material, but zinc does not rust: an important quality for public sculptures.  Wanting to improve the perception of zinc as an artistic medium, foundries and cemetery monument makers renamed zinc "white bronze."  After a short period exposed to the elements, zinc-oxide forms on the surface of the monument, protecting the zinc underneath and creating a white patina.  see Zinc Sculpture in America, 1850-1950, By Carol A. Grissom, and White Bronze Grave Marker
Photo by M. Johnson

1 comment:

  1. It should also be noted that eating zinc is very important. Without a health quantity of zinc in a child's meal, the child is more susceptible to infections and may suffer from diminished growth and delayed sexual maturation.