The cast stone arches by Alexander Calder that adorned Caltech’s Throop Hall fell victim, as did the building itself, to the 1971 San Fernando earthquake. The large allegorical figures representing, from left, Nature, Art, Energy, Science, Imagination, and Law with their elaborate framing elements lay neglected for years, exposed to all weather in Pasadena’s City Yards.

Various schemes for their incorporation into city buildings came to nothing. Finally in 1986 the arches were rescued by Caltech and artfully restored as part of a bridge between Crellin and Church laboratories in a reconstruction project that yielded the new Arnold and Mabel Beckman Laboratory of Chemical Synthesis.

Symbolizing the connection between past and present, and between chemistry and its related biological disciplines, the arches hark back to their original purpose, in Calder’s words, “to give plastic utterance to the aims and scope of the school.”