Holton Rower's Pour recalls the lysergic 1960s at their most saturated. So much so that, had Timothy Leary been an abstract expressionist, it's easy to imagine that his work might have borne more than a passing resemblance. The process is essentially self-evident: build a flat, geometrical sculpture and pour cup after cup of paint on it. Gravity does the rest. But, gee, what an effect!