LIKE MANY World War I fighter pilots returning from Europe in 1919, Wesley Smith hoped to find a career that would keep him aloft. He had flown missions out of England during the war. Afterward he settled in Philadelphia and found work as a pilot for the brand new Aero Service Corporation, which had been founded in July of 1919 and was struggling to survive by delivering packages and taking passengers on joyrides. The company would have failed several times if Miss Mary K. Gibson, a Main Line socialite, had not given generously of her faith and fortune. During even the hardest times, Miss Gibson treated her pilots to handsome leather jackets and helmets.

Raised in Maybrook, her father’s sprawling, castellated mansion, she knew well the pride Philadelphia’s families took in their estates. She soon hit on the idea of charging families like the Stotesburys and du Ponts one hundred dollars for aerial views of their mansions.

Up in Trenton another veteran pilot named Virgil Kauffman had embarked on a very quiet postwar career of searching property titles for a realtor. Kauffman had learned aerial photography in France and, after a few years in the dingy halls of the Trenton courthouse, was ready to return to the skies. When Miss Gibson offered him fifty dollars a week and all the flying he wanted, he signed on.

The Aero Service pilots soon had as much business as they could handle. Based at a primitive airstrip alongside the Baltimore & Ohio tracks, they rarely had time to visit the company’s headquarters downtown, where a handful of other employees solicited customers, printed the pictures, and managed the orders. Customers were everywhere: industrial plants, schools, real estate developers, utility companies, and insurance firms, as well as the proud owners of Edwardian estates. Before long Aero Service outgrew its airstrip. Smith kept pleading with Miss Gibson to invest in a larger one, and by 1927 she gave in. Soon after, Smith left the company to manage the new field, and Kauffman bought out Aero Service.

Oblique photography was the bread and butter of the company through the 1930s. At first Kauffman knelt in the cockpit, camera held firmly in the wind as he glided past the target. (The engine was temporarily shut down to reduce vibration.) He experimented with a camera mounted on the wing of his biplane; another of the airmen flew with the bulb of a pneumatic shutter-release in his mouth.

By the mid-1940s Kauffinan was taking an aerial magnetometer on his flights instead of a camera. The instrument had been used during World War II to locate submarines; Kauffinan turned it into a tool for the mining industry and converted unbelieving Bethlehem Steel executives by locating a fourteen-hundred-foot-deep deposit that produced a billion dollars’ worth of ore. Aero Service thrived, moved to Houston in 1961, and now works exclusively on geophysical research.

Until recently Virgil Kauffman had been storing the negatives from the