Since the mid-1970s Richard Serra has been exploring the sculptural fundamentals of mass and gravity to create sculpture that produces a simultaneous sense of balance and precariousness. Prop (1968), for example, consists of a 60-inch-square sheet of lead that is held flat against the gallery wall and about three feet off the floor by a rolled lead cylinder that leans against it. The apparent instability of this arrangement leads the viewer to focus on the weight of the lead sheet and on the simultaneous assertion and defiance of the force of gravity. Serra's Garden work, Five Plates, Two Poles (1971), produces a similar kind of tension. While this sculpture is indeed stable, the five large steel plates propped up against each other appear to be in danger of toppling.
 
 

Five Plates, Two Poles 1971
Cor-Ten steel

acquired from the Leo Castelli Gallery, New York, 1984
(gift of Judy and Kenneth Dayton 84.1147)