For a time, Washington, D.C., had a mystery hanging over it.
In the western sky, residents saw a strange light that seemed to take the form of a flaming sword, suspended above the city and pointed downward. To some, it must have looked ominous, almost biblical, the sort of thing that would have set imaginations running in an age when strange lights in the sky still carried a deep sense of wonder and dread.
But the “flaming sword” was not a warning from the heavens. It allegedly was a searchlight.
In October 1925, the mystery was traced to Company C of the 29th Engineers at Fort Humphreys, Virginia. The soldiers were using powerful searchlights for a new method of nighttime surveying across hundreds of square miles of Virginia.
By placing lights miles apart and pointing their beams straight upward, the engineers created enormous triangles of light in the night sky. From those glowing markers, they could calculate longitude, latitude, and other surveying data with remarkable precision.
‘Flaming Sword’ in Heavens Revealed as Searchlight
Washington, D.C. — The mystery is solved!
Washington is not threatened by a flaming sword in the western sky, suspended over the city.
Professor Asaph Hall, of the U.S. Naval Observatory, was right about the mysterious light appearing in the west and which, at times, looks like a sword pointed downward. Hall said it was a searchlight.
It is.
Company C, 29th Engineers, Fort Humphreys, Virginia, has explained the mystery. The light in the west comes from searchlights used at night in surveying, by a new method originated by the 29th Engineers.
This company is surveying 400 square miles in Virginia, starting at the Potomac River. It is now working near Quantico, proceeding toward Warrenton.
The searchlights, used in the new method, point directly up. Here’s how the engineers do night surveying by the new method:
The territory to be surveyed is divided into triangles by the rays of powerful searchlights.
By day, points are established at which the lights are to be located. This is done from maps.
The lights, placed 20 miles apart, are turned on at dark. The rays are more accurate mathematically than any surveyors’ lines made in the ordinary way, over the actual countryside. A wood might deflect a surveyor’s line; nothing can deflect the searchlights.
Within this20-mile triangle, observations are taken and longitude, latitude and other surveying data computed. When one triangle is completed, the searchlights are placed again, and another triangle is formed and studied.
Source: The Washington Daily News. Washington, D.C. October 20, 1925.
