LONDON — A Henry Moore sculpture is an oddly familiar sight. Its size and scale, weight and heft; the undulating curves and geometric angles that recall both the specificity of the human figure and the abstractness of large-scale landscape — these elements are present in Moore’s work on public plazas and piazzas, in front of city halls and banks, public squares and parks, all over the world. “More than any other artist of our own time,” John Russell wrote in The New York Times in 1983, “he has been brought out of the museum and into the open and offered the gift of ubiquity.”