National Geographic : 1983 Nov
unknown, and he was simply too careful a man to experiment recklessly. I suspect that nature was also a culprit behind the decay of the "Last Supper." Consider that the years during which Leonardo was painting had exceptionally dry winters. We know, for in stance, that the nearby Alps were free of snow. So the plaster may have dried faster than usual, causing the priming to crack eas ily, and the paint along with it. Although the "Last Supper" was immedi ately acclaimed upon its completion in the late 1490s, by 1517 it was known to be flak ing. Several large-scale copies were com pleted during Leonardo's lifetime, including at least two by his students. King Francis I of France ordered a copy, as well as a tapestry version, as a gift to the pope. By 1587 the painting was described as "half-ruined." In 1652, perhaps because the friars thought the "Last Supper" was lost, they enlarged a small door beneath the mu ral. In doing so, they cut off Christ's feet. Still the painting remained one of the most celebrated works in Europe. In the 18th cen tury the friars put a curtain over it, which they would pull open for visiting dignitaries. The curtain, of course, scratched the flaking mural. It also trapped humidity. In fact, 18th-century reports allege that "rivulets of water" ran down behind the curtain. About the same time, the friars initiated the first so-called restoration. In 1726 they engaged a painter, Michelangelo Bellotti, who was almost unknown, to repaint the original entirely. His work proved so in competent that another painter, Giuseppe Mazza, was asked in 1770 to remove Bellot ti's overpainting with a scalpel. A visiting Irish artist, James Barry, saw wall (right)supports sensors that record vibrationsset off by changes in temperature and humidity. Air conditioningis needed to control such shifts as well as pollution and mold. At the level of the lunettes, architect Roberto Cecchi, left, consults with Lionello CostanzaFattori,director of the agency in charge of the wall. The authorheads the department responsiblefor the painting,while anothergroup monitors the building. Wall cracks detailed here (above right) have been largely contained. Restoring the "Last Supper"