In a helicopter above the city on Friday, Stephen Wiltshire of London looked down at the streets and sprawl of New York. He flew for 20 minutes. Since then, working only from the memory of that sight, he has been sketching and drawing a mighty panorama of the city, rendering the city’s 305 square miles along an arc of paper that is 19 feet long. He is working publicly in a gallery at the Pratt Institute in Brooklyn.'I always memorize by helicopter,' he said on Tuesday, pausing from detailing the corners of a street on the Brooklyn side of the Williamsburg Bridge.Mr. Wiltshire sees and draws. It is how he connects. Until age 5, he had never uttered a word. One day, his kindergarten class at a school for autistic children in London went on a field trip. When they came back, he spoke. “He said, 'Paper,' - his sister, Annette Wiltshire, said. 'The teacher asked him to say it again. He said it. Then they asked him to say something else, and he said, 'Pen.'With pen and paper in hand, he drew what he had seen that day. In time, a clever teacher taught him the alphabet by associating each letter with a place he had drawn 'a' for Albert Hall, 'b' for Buckingham Palace, and so on.What did he use for 'z'? Mr. Wiltshire looked puzzled.'Z' that's the same as zed,' his sister interjected, pronouncing the letter the British way.'Zed,' Mr. Wiltshire said. 'That was the zoo.'Now 35, he has already drawn eight major cities after flyovers. He has his own website and gallery. By unpacking in exquisite detail the riches that he absorbs in a glimpse, Mr. Wiltshire has built a bridge to the world that had once been cut off to him.The family was more concerned in those days with finding a school where he could learn to read and write. Later, they wanted him to master the London subways, to cope with diversions or delays that might interrupt his fixed routines. After the school entered his artwork in competitions, his talents began to get attention: he was featured in a BBC program, 'Fragments of Genius.'. 'The Early Show' on CBS brought him to New York for his current project.'That he has a gift makes no sense at all to Stephen,' Ms. Wiltshire said. 'He knows that he draws very well, but he picks that up from other people he sees the warmth on their faces, they tell him how much they like his work, and that makes him very happy. He loves the attention.'The elements of New York that he had captured in the first four days included most of Manhattan, the Hudson shoreline of New Jersey, the George Washington and Verrazano-Narrows Bridges, Ellis Island, the bridges to Queens and Brooklyn. 'Section by section,' he explained.Ms. Wiltshire elaborated. 'He cuts the drawing into segments, then fills each one in,' she said. 'We will all see the same thing, but we focus on what is of special interest. For Stephen, it's like a sponge where he absorbs everything but he doesn't squeeze out the rest.'He occasionally does a portraits of himself or of his sister, Mr. Wiltshire said. But most of the images he creates are of structures, given life by his hand and eye. As he worked on Tuesday afternoon, he often turned to glance at the people watching. He gave a panoramic smile. (via New York Times