Science / Medicine : Peary’s Place Beyond a Shadow of Doubt : Exploration: His claim of reaching the North Pole was proved by analyzing photographs to determine the angle of the sun’s rays.
In 1917, Merchant Marine Capt. Thomas Hall tried to debunk Admiral Robert E. Peary as the first explorer to reach the North Pole, insisting that the shadows on Peary’s published photos did not look as if they could have been taken on top of the world. “Shadows are nature’s witnesses,” Hall wrote. “They never lie.”
Now, the shadows have come to the fore once again, but this time to the benefit of Adm. Peary. After a yearlong study sponsored by the National Geographic Society, the Navigation Foundation cited the shadows as significant evidence for its conclusion last week that Peary was not a fraud, but reached the pole on April 6, 1909, just as he said he did, in one of the most celebrated and courageous moments in the history of exploration.
The intense study of the photos, using a trigonometric technique developed during World War II, marked a novel way of looking at the issues in the long and bitter controversy over the validity of Peary’s claim.
The foundation’s conclusions have not been accepted by Peary’s most persistent critics, such as Baltimore astronomer Dennis Rawlins, who insists that the images are too fuzzy and the margin for error too great for the photographic analysis to count as evidence. But the thoroughness of the foundation’s lengthy report may prove persuasive in the long run.
When Peary published his photos in his book “The North Pole,” the editors tried to highlight the images of the members of Peary’s team, consequently washing out most of the shadows in the snow. Hall was thus looking at inadequate and distorted pictures when he made his judgment about where they had been taken.
But the Navigation Foundation--a small organization founded and led by 75-year-old Thomas D. Davies, a retired rear admiral and former assistant director of the U.S. Arms Control and Disarmament Agency--found a large number of Peary’s North Pole photos in the files of the National Geographic Society. The shadows appear clearly on these photos.
The system used by the foundation is complex. But it works on the simple principle that a line drawn from the top of an object to the top of its shadow will follow the same path as a ray from the sun.
In one photo of two Eskimos at the North Pole, for example, the foundation drew a line connecting a tuft of fur on the right knee of one Eskimo with a shadow of that tuft. It then drew other lines connecting the edges of small mounds of snow with the edges of the shadows of those mounds.
All of the sun’s rays are parallel but, like parallel railroad tracks, they always seem to converge when drawn in perspective on a two-dimensional picture. The foundation drew lines on the photo until they converged into what is known as a vanishing point somewhere off the photo. That vanishing point was the exact location of the camera taking the picture.
Once the vanishing point, the camera’s focal length (the distance between the lens and the film) and the angle of the camera from the horizon are known, a trigonometrist can figure out the angle between the horizon and the rays of sun streaming into the camera. That angle shows the height or elevation of the sun.
In the case of the photo of the two Eskimos, the angle of elevation came to 6.45 degrees. Astronomers have long been able to plot the elevation of the sun at different parts of the Earth at different times. The Nautical Almanac for 1909 makes it clear that at the North Pole the sun would have had an elevation of 6.42 degrees on April 6 at 10 p.m.--the approximate time that Peary was supposed to have taken the photo. In short, judging by this photo, Peary, the photographer, would have been practically on top of the North Pole.
The Navigation Foundation analyzed 13 photos taken in three sets at three different times during the Peary team’s stay at the pole. Averaging the elevation determined for each photo and then narrowing down the location by comparing the three sets with each other, the foundation concluded that the photos “place Peary within four or five miles of his reported position and certainly no more than 15 miles away.”
Considering the instruments used in those days, scientists agree that this would have put the American hero close enough for all to say that he had achieved his lifelong goal and could boast, as he did in his dispatch to the news agencies, “Stars and Stripes nailed to the Pole!”
