The summit station at El Misti, Peru (19,200 feet)

"The night is passed at the hut, and the final ascent to the summit made on the second morning. This occupies several hours, as the animal stops to rest every fifteen or twenty feet at this altitude. On two occasions I was obliged to walk a short distance to cross snow which had drifted across the path, and realized the extreme difficulty of breathing during the exertion required."

"The effect of the altitude upon me was chiefly to cause headache, sleeplessness and partial loss of appetite. On one occasion while at the summit I experienced a decided feeling of faintness for a short time."

- Winslow Upton, Physiological Effect of Diminished Air Pressure, Science, 27 December 1901

Misti summit station, Jan. 5, 1894.
Shut in by cloud [and] snow looking N. E.

During the academic year of 1896-97 Prof. Winslow Upton took sabbatical from his work as Director of Brown University's Ladd Observatory. He spent ten months at the new southern station of the Harvard College Observatory (elevation 8,050 feet) in Arequipa, Peru. His primary goal was to measure the geographical position of the station before astronomical observations could commence.

During this time he also made four ascents to the summit of the dormant volcano El Misti, which was the site of recording instruments (pictured above) maintained by Harvard. At the time it was the highest meteorological station in the world at an elevation of 19,200 feet.


(According to the account of Francisco Velez the five foot tall cross of iron in the photograph above was placed there by Bishop Miguel Gonzalez de Pamplona in 1784. It had belonged to the Monastery of Santa Teresa de Jesus which had been destroyed by an earthquake.)

The meteorological observations from the summit of El Misti indicate that the barometric pressure was typically about 14.9 inches Hg, just 50% of the pressure at sea level. The low level of oxygen in the air caused great difficulty for the observers who climbed to the summit and the mules that carried their equipment.

Ascent of El Misti

Photo credits: Peruvian Meteorology, 1888-1890.
Annals of the Astronomical Observatory of Harvard College, 1899.
The original photographs are preserved at the Harvard University Archives.

Note: I originally published this on the Ladd Observatory Weather Underground blog in 2011. I expanded on this topic for a talk at Necronomicon Providence in 2013; the slides for my talk are at Cosmic Inspiration: Lovecraft's Astronomical Influences.