- Karen Cummings
Resurveying the Presidentials
If, standing atop Mt. Washington, you always thought your elevation above sea level to be 6,288 feet, or 5,698 on Mt. Adams, or 5,715 on Jefferson, it's time to question that assumption.
Most of the survey work and mapping of the Presidential Range by the U.S. Geological Service has not been reviewed for decades, in some cases not for 80 years, explained Alan Smith, president of the Mt. Washington Observatory. In light of these facts, the Observatory is cooperating in an effort to update the accuracy of the data.
"It's not that the elevations of the mountains have changed notably during that period," Smith remarked, "but we have equipment at our disposal that simply was not available then. As incredible as it seems, some of the original survey work was done by eye, taking a sighting and then a cross reading," he continued. "This sort of approximation had historically been the weak link in the surveying process."
The prime motivator behind the project has been Bradford Washburn, director of the Boston Museum of Science, noted international mountaineer, and who, according to Smith, is one of the world's leading cartographers. "Washburn had had a lifelong love affair with the Presidentials," the Observatory's president continued. "He's always been curious about the accuracy of this information, and since the equipment is available to check it, it seems logical to do so."
Washburn's cartographic skills developed through his involvement with mountaineering and the need for accurate maps in that pursuit. He climbed extensively in the White Mountains in the 1920s, and furthered his education in cartography during college. Washburn was a part of numerous early expeditions to then unknown and unmapped peaks throughout the world, "and is noted for his authoritative mapping of Mt. McKinley, and more recently of the Grand Canyon." His adventures in the Grand Canyon region are documented in the July 1978 issue of National Geographic.
The Mt. Washington Observatory is a non-profit corporation founded in 1932 to conduct scientific research in the Presidentials and specifically on the summit of Mt. Washington. Currently, the Observatory is involved in projects ranging from meteorological research to experiments with alternative energy systems. A new building is under construction atop Mt. Washington that will house the Obs, and its Summit Museum, and in an effort to foot its portion of the bill, members of the Observatory initiated a fundraising campaign early last winter.
Washburn has been an avid supporter of the Mt. Washington Observatory since its establishment and, as a means of supporting the current fundraising efforts, presented a benefit lecture in Boston on his Grand Canyon project. Afterwards, he and Smith began to discuss the possibility of a similar undertaking for the Presidential Range. With the accuracy of distance and elevation measurements in question, the Observatory threw its support behind Washburn, and the effort was under way. "We're taking the old data, resurveying, and feeding the information back to the USGS," Smith explained. "The end result may simply be a revision of the records, or if it seems proper, a remapping of the Presidentials."
Washburn's first step was to devise a network of 22 peaks in the Presidentials as key points to measure the altitude and distances between the other mountains. Next, aerial photographs had to be taken, and an elaborate method to pinpoint the summit of each peak so that it would show up in the photos was developed. Over the course of the summer, largely through the volunteer efforts of members of the Observatory, the Appalachian Mountain Club, Alan Smith, his wife Lydia, and Barbara and Brad Washburn, jibs, or triangular sails on wooden frames,were packed up to the top of each of the 22 peaks. The framework was set up so that the lower point precisely indicated the summit, which is marked by a small brass USGS plate, driven into the rock, stating the elevation, longitude, and latitude. Two weeks ago the sails were simultaneously unfurled and aerial surveys were taken. "The resulting photographs revealed an arrow pointing exactly to the summit," Smith explained.
The next step, already under way, is to physically make exact measurements between the network of 22 peaks, after which the elevation, and distance between all other points on the aerial survey can be computed. The measurement process involves drilling a hole three inches deep and one inch in diameter, into which a steel rod is inserted to hold a prism. An electronic laser device is then utilized from the summit of another of the 22 to beam a ray of light to the prism, which reflects it back to the initial point. The length of the beam can be calculated to within 1/100 of a foot.
The equipment required for the project is massive. Aside from the drilling rig, the laser requires a 60 point portable generator, and numerous volunteers have been packing the weighty stuff from peak to peak. Lately, a helicopter has been used to facilitate the project, since it's hoped that this initial stage will be completed by the end of 1978.
Once the first phase is done, and the data compared to the old records for accuracy, a decision will be made whether or not a remapping of the Presidentials is necessary. "The surveying is a very small step in the overall effort," Smith stated. "It's really an educational process, after which we'll make other choices."
"Our immediate purpose is to update the current information using the most modern equipment available," Smith emphasized, continuing to explain that the project is largely a purely scientific pursuit. "But it is a personal thing, too," he said. "This is a part of the world many people are very fond of, and it only makes sense to have the most accurate information possible about it."
Postscript: Brad Washburn passed away at age 96 in 2007. Here is more information on his many accomplishments during his life.