Leonardo da Vinci as engineer and architect. This Italian Renaissance man is generally thought of first for his painting and sculpture, but Montreal's Museum of Fine Arts is displaying drawings that show his interest in fields far removed from the arts.

Leonardo da Vinci's genius for painting and sculpture has often eclipsed his equally impressive talents as an engineer and architect of the late 15th and early 16th centuries. His huge output of sketches, detailed drawings, and notes span an amazing variety of subjects and were prophetic visions of machines and architectural principles to be realized centuries later. From his birth in 1452 until his death 67 years later, da Vinci produced a prodigious number of drawings, moving with equal assurance in technology, art, nature, music, architecture, and poetry.

In da Vinci's 15th-century Italy, engineers had no formal training, but learned by hands-on projects, often war-oriented like siege machines and crude tanks. After his death in 1519, Leonardo's works were scattered throughout Europe.

Montreal's Museum of Fine Arts has opened a unique international exhibition of da Vinci's folios, occupying an entire two-story wing and titled ``Leonardo da Vinci, Engineer and Architect.'' More than 500,000 visitors are expected to see it before it closes in November.

The handsomely mounted show was conceived four years ago as a tribute to Canada's 1987 centennial celebration of the engineering profession.

In 1983, museum director Pierre Th'eberge and Bernard Lamarre, museum chairman and chairman of the Canadian Engineering Centennial Board, began the tremendous task of preparing for the exhibition, which opened in May.

They agreed to focus on Leonardo's wide-ranging interests in engineering and architecture, embodied in his studies of geometry, mathematics, mechanics, physics, and anatomy. Contributors of the materials from 16 collections include the West Germany, France, Italy, Spain, Switzerland, and the United States.

Notable collections include the Royal Library at Windsor, London's Victoria and Albert Museum, and the Armand Hammer Foundation in California.

``We chose Leonardo to dramatize the centennial of the engineering profession in Canada and because we wanted to show that engineering and architecture are as much products of the imagination as is painting,'' Mr. Th'eberge said.

The exhibition is enhanced by 25 models, a number of them life size, of Leonardo's studies, created independently from plans by craftsmen from Florence and Canada using materials of the 16th century. We saw schoolchildren and guides touching the larger models to get the feel of the mechanical principles demonstrated. Panels and video demonstrations explain the functioning of the large machines.

Included are a reversible hoist and revolving crane, a rack and pinion, a three-speed gear, a spring motor driving a vehicle, an alternating movement, cranes, water meter, a ball bearing, a crankshaft, and a 12-foot-high model of a centrally planned Milan church, never built. The drawings themselves are in a sepia tone, each one a miniature piece of artistry, with Leonardo's 15th-century writing.

Pages of the codices (notebooks) will be turned occasionally to provide varied displays. Also included is the work of other leading Italian contemporaries of da Vinci, several of whom influenced his creativity.

We were particularly interested in Leonardo's hand-colored topographical map and plan to reverse the flow of the Arno River, his detailed city plan drawn for patron Cesare Borgia, and the model of the Milan church.

As the exhibition captions make clear, few of Leonardo's architectural projects were ever carried out. In a museum publication announcing the opening, guest curator Jean Gillaume, director of the department of art history at Fran,cois-Rebelais University in Tours, France, explains that da Vinci ``was interested in concepts and new ideas and asked questions that did not correspond to the preoccupations of his contemporaries.''

But his solution to reinforcing the heavy central dome of the Milan church was completely practical and could have been built exactly as designed, Mr. Gillaume says.

Another da Vinci expert, Carlo Pedretti, Armand Hammer professor of Leonardo studies at the University of California in Los Angeles, wrote in the publication that da Vinci's most important and enduring contribution to our civilization is ``the lesson we learn from his insatiable curiosity about the way nature works and the great respect he felt for it.''

Mr. Pedretti urges readers, ``In this technological era, we should never forget that machines are for man's use and that mankind should always maintain absolute control over technology in order to conserve nature.''

There is a 400-page, cloth-cover catalog, published in French and English ($49.95) with 436 illustrations, 23 in color. The book includes essays by 10 of the world's foremost da Vinci scholars.

Children will enjoy the 36-page catalog ($7.95) written especially for them, with illustrations and an engaging text.

The museum also conducts summer weekday workshops about da Vinci's drawings. Separate sessions are held for children, adolescents, and adults on Tuesdays, Wednesdays, and Thursdays through Aug. 27.

Museum hours are Tuesday through Sunday from 10 a.m. to 10 p.m. The museum is closed Mondays.

For more information about the da Vinci exhibition, write the Montreal Museum of Fine Arts, 1379 Sherbrooke Street West, Montreal, Quebec H3G1K3, or phone (514) 285-1600.