Artists, jealous of the birds, used to peer from steeples, imagining what man might see if only he could fly.

The aerial photographs displayed at the National Air and Space Museum would surprise them.

In the Bird's-eye views the artists painted, walls run straight as strings, castles look like dollhouses, and the earth seems somehow man-made, miniaturized. From airplanes or outer space, it does not look like that at all.

It seems, instead, a living thing, oddly colored and patterned, cellular, organic. At first, it's hard to tell if the handsome colored photographs were taken from an airplane or through a microscope.

The 19th-century ballonists, who took photographs from gondolas, and their ingenious colleagues, who launced cameras with kites - and the Germans who, in 1908, strapped 2 1/2-ounce automatic cameras to the breasts of postal pigeons - discovered that their pictures only distantly resembled the ground they thought they knew.

Aerial photographs are disconcerting. They lack a foreground (unless, of course, one counts the blurs of pigeons's wings), and straight horizon lines seem to curve. The rectangular frames in which they hang imply, as all frames do, windows, open doorways, and a sense of top and bottom that is contradicted by the ways things look seen straight down. Would these photographs look completely different if displayed beneath a thick glass floor?)

The first aerial photographs presented the familiar. The oval view of Boston, with which the exhibition opens, was made in 1860 from the Queen of the Air balloon. Ascending in another, Nadar, the famous portraitist of Paris, photographed the Arc de Triomphe in 1868.

George R. Lawrence's sweeping view of "San Francisco in Ruins" was made six weeks after the famous earthquake of 1906. He used 17 linked kites to send his panoramic camera aloft.

Five years later, the first known photograph from an airplane was made by Lt. G.E. Kelly, U.S. Army, above the same city. Kelly photographed the ground with his hand-held camera; he also shot his shoes. The first known rocket photograph was made in 1912 by a group of German soldiers, using gunpowder for fuel. When their rocket's nose-cone disengaged, the camera that it contained took a picture of the earth, from 2,600 feet, as it parachuted down.

The National Geographic Society's Melville Bell Grosvenor, riding in a dirigible in 1930, took the first color aerial photograph: Washington, D.C. in muddy browns and greens. Most of the exhibit is devoted to the work of four contemporary artists - William Garnett, Robert Buckham, George Gerster and George Hall. Color rules their show.

Many of the pictures by Buckham and Garnett seem to be abstractions, though, of course, they're not. The California mud flats photographed by Bucknam in 1969 have the look of sperm; his photograph of leaching ponds brings to mind red blood cells. While piloting his Cessna, Buchnam takes his pictures through the airplane's open window. Garnett is a pilot, too. He is represented here by pictures of Old Faithful, of snow drifts in Death Valley, and by a lovely shot, in black and white, of a skein of Snow Geese with the reflection of the sun.

Both George Hall (who shoots from Goodyear blimps) and the Swiss-born Gerster often included scale-setting clues in their pictures. Consequently the photographs that Hall makes of rowboats in Paris and boxcars in Kentucky are not difficult to read. Nor are Gerster's tightly composed shots of skiers and flamingos. In Gerster's handsome picture of an African village in Mali, one can recognize the warrior by the shadow of his spear.

The set of NASA photographs with which the exhibition ends, though they are not works of art, have a special, almost inadvertent beauty.Some were made by astronauts circling the earth, some by the unmanned Landsat satellite. Included are "false color" pictures based on Landsat photographs taken from an altitude of 570 miles. They were shot in black and white; strong colors were arbitrarily assigned to specific shades of gray, and computers made the brilliantly colored photographs that are here on display. They show flash floods in Arabia, the Nazca lines drawn centuries ago on the highlands of Peru, and the shores of the Dead Sea.

Also on display are a 10-foot-long transparency of the Grand Canyon and a 1972 NASA shot, in infrared, of this city and the Mall.

One extraordinary picture here - of the earth and moon together, taken from a distance of 7.25 million miles - is no more disorienting than any simple portrait. It does not seem to be an aerial photograph at all.

"Our Beautiful Earth: The View From Air and Space" was organized by James Dean and Bill Good of the museum's staff. It will remain on view a year. CAPTION: Picture 1, "San Francisco in Ruins," by George R. Lawrence; Picture 2, Snow Geese with the reflection of the sun, by William Garnett