Obituary:Jean Gimpel

Jean Gimpel was a man of great physical and intellectual energy, with a big heart and strong sense of justice. A profound and very practical interest in technology, and especially that of the Middle Ages, was the thread that ran through his working life. It yielded two classic studies, The Cathedral Builders (1958) and The Medieval Machine: the Industrial Revolution of the Middle Ages (1976), underpinned two further books, The Cult of Art: against art and artists (1968) and The End of the Future (1995), and helped make him an effective saboteur in the French Resistance. For his services during the Second World War he was awarded the Croix de Guerre, the Medaille de Resistance and the Legion d'Honneur.

Gimpel liked to say that he lived between four cultures: those of France, England, the United States and the 13th century. He was born in Paris in 1918, the third son of the well-known art dealer Rene Gimpel, a friend of Monet, Renoir and Proust whose journals he would eventually edit. His mother was the sister of an even more famous English dealer, Lord Duveen. His two brothers, Peter and Charles, who was captured and tortured by the Germans and died in 1973, founded their own gallery in London in 1946.

Initially Jean shared the family enthusiasm for art, and contemplated a career as an expert on the chemistry of Old Master paintings. Eventually, however, he decided to combine earning a living as a diamond broker, first in Paris and then, from 1963, in London, with writing. His research for The Cathedral Builders confirmed his revulsion against art, later spelt out in his book-length diatribe The Cult of Art. Compared with the nameless craftsmen and unsung engineers and architects of the Middle Ages, artists from the Renaissance onwards were, he argued, egotistic and self-indulgent, if not actually fraudulent: for example, many of Leonardo da Vinci's "inventions" were borrowed from treatises by earlier engineers. To deify such pedlars of dispensable luxuries was, he believed, as logical as worshipping relics.

The Cathedral Builders was written in French as Les Batisseurs de Cathedrales and sold more than 100,000 copies in France alone. In addition to being stuffed with fresh and fascinating information, it demonstrated that France's great cathedrals were built not just to the glory of God but by the finest professional architects and craftsmen of the time.

In The Medieval Machine, a broader study, he sought to demonstrate that the technological revolution of the Middle Ages, focused on mills and especially water-mills, was no less remarkable than the Industrial Revolution. He found many striking parallels between the technological boom of the 10th and 13th centuries in Western Europe and the one that started around 1750.

After detailed comparison of parallel developments in France between 1050 and 1265 and the United States between 1850 and 1953, he concluded that America had subsequently entered a period of terminal decline that would bring Western civilisation down with it. These Cassandra-like warnings were the focus of an international conference on the decline of the West in Los Angeles in 1977 and were amplified in his last book, The End of the Future.

Gimpel was a man of deeds as well as words. Dismayed by the pre-medieval level of technology in the rural areas of many Third World countries, he sought to introduce patchily known inventions such as the Archimedean screw for lifting water from one level to another. To explain their benefits across language barriers he revived the concept of three- dimensional models, establishing in 1977 a charitable project, Models for Rural Development, to propagate them in partnership with Appropriate Technology Ltd. A miller in the foothills of the Himalayas, for example, rapidly recognised the greater effectiveness of the spoon-shaped blades of a 19th-century Romanian water-mill when compared with the 2,000-year- old Nepalese version. The former was soon adapted as part of the Nepalese government's five-year plan.

Gimpel also devised models to show how not to do things, such as allowing animals too close to a well, or coughing TB-infected sputum over children. These "negative" models were extensively used on the Indian subcontinent and in Africa.

Gimpel loved the stimulus of intelligent friends, especially female ones, and he and his wife Catherine, a Breton and former fellow Resistance member whom he married just 50 years ago, held a kind of Sunday afternoon salon several weeks of the year at their Chelsea Embankment flat. Among the assembled writers, scientists, doctors, historians and the like, their volatile host moved, firing off his enthusiasms and prejudices in rapid, French-accented bursts.

Few people can have more effectively or agreeably bridged the gap between C.P. Snow's "two cultures" of science and the humanities.

Jean Victor Gimpel, historian of technology: born Paris 10 October 1918; married 1946 Catherine Cara (two sons, one daughter); died London 15 June 1996.