photographs of a factory workers' lunchroom and a restaurant progressively crowded with diners. His 1973 show at the John Weber Gallery in New York expressed the Fibonacci in a series of low modular tables. In 1990 the sequence determined the form of a spiral assembled from sticks, iron and paper across 24 meters of a hall in Prato, near Florence. An installation of Fibonacci numbers by Merz is the landmark of the Centre for International Light Art in Unna, Germany. Merz became fascinated by architecture: he admired the skyscraper-builders of New York City; his father was an architect; and his art thereby conveys a sensitivity for the unity of space and the human residing therein. He made big spaces feel human, intimate and natural. He was intrigued by the powerful (Wagner, D’annunzio) as well as the small (a seed that will generate a tree or the shape of a leaf) and applied both to his drawing. In the 1960s, Merz's work with energy, light and matter placed him in the movement that Germano Celant named Arte Povera, which, together with Futurism, was one of the most influential movements of Italian art in the 20th century. In 1968 Merz began to work on his famous igloos and continued throughout his life, revealing the prehistoric and tribal features hidden within the present time and space. He saw the mobility of this typical shelter for nomadic wandering as an ideal metaphor for the space of the artist. The neon words on his igloos are hallmark Italian phraseology: like "rock ‘n’ roll," they have the power of being the more than catch phrases or slogans, but the voice of his time in history. His first of the dome-shaped structures, "Giap's Igloo," in 1968 was decorated with a saying by General Vo Nguyen Giap of North Vietnam: If the enemy masses his forces, he loses ground. If he scatters, he loses force. By the time of his first solo museum exhibition in the United States, at the Walker Art Center, Minneapolis, in 1972, Merz had also added stacked newspapers, archetypal animals, and motorcycles to his iconography, to be joined later by the table, symbolizing a locus of the human need for fulfillment and interaction. From the late 1970s to the end of his career, Merz joined many artists of his generation in returning periodically to more conventional media. In Le Foglie (The Leaves) (1983–84), measuring