AERIAL MAP OF MANHATTAN

MAPPING FROM ABOVE

The first photograph taken from the air was shot from a 80 metre-high hot-air balloon in 1858. It was an inauspicious start – and that photo of a small French village was lost – but aviation would revolutionise map-making. From above, a photograph could gather a huge amount of data at a time, a major improvement on labour-intensive ground surveys.

When World War I broke out, maps became powerful weapons. A detailed trench map of the front line allowed for artillery bombardments to be carried out without practice shots, retaining the element of surprise.

After the war, aerial photography spread to civilian use and the Fairchild Aerial Map of Manhattan ushered maps into pop culture consciousness. New York City entrepreneur Sherman Fairchild, who had been developing new aerial photography techniques for World War I, introduced an aerial camera that automatically snapped photos and turned the roll of film at timed intervals.

Mounted under a war-surplus biplane flying 10 000 feet high over New York, the camera snapped photos of the city every 27 seconds over a 69-minute flight up and down the island. The negatives were then overlapped to form the detailed Manhattan grid with a precision that set the standard for the next 50 years of aerial mapping.

Manhattan was Fairchild's second aerial survey. His first, a map of Newark, New Jersey, failed to gain notice. popularmechanics.co.za