The Aletschhorn was climbed first in 1859 by Francis Fox Tuckett, J. J. Bennen, V. Tairraz and P. Bohren. The party passed the night in some holes in the rocks above the Mittel Aletsch Glacier (on the east side of the mountain), and on the following morning, on 18 June, started the ascent and reached the snow arête connecting the Dreieckhorn with the main peak. The passage along this arête at a so early period of the year, before the snow has become well consolidated, involved some risk and a slope of névé lying at an angle of 50°, required care and good step-cutting. But the summit could be reached without too much difficulty. Like many other climbers, Tuckett took with him a barometer and made scientific observations. He noted the icy temperature and the very strong wind, blowing the snow and threatening to knock over the climbers.