The daily labour of the whole party was measuring the length of this plain in a horizontal direction, while the inequalities of the ground were at the same time corrected by means of a level. They commenced their task early in the morning, and, unless when interrupted by bad weather, or the too intense heat of the sun at noon, continued actively employed until the evening. The plain of Cazambe had first been made choice of; but after a short trial, during which M. Couplet, one of the French academicians, died suddenly, this position was abandoned. It was now determined, therefore, to continue the series of triangles to the south of Quito, and the whole company dividing itself into two parties, the one to which Don George Juan was attached proceeded to the mountain of Pambamarca, while Ulloa, La Condamine, and Bouguer climbed up to the highest summit of Pichincha. “Our first scheme,” says Ulloa, “for shelter and lodging in these uncomfortable regions, was to pitch a field-tent for each company; but on Pichincha this could not be done, from the narrowness of the summit, and we were obliged to be contented with a hut, so small that we could hardly all creep into it. Nor will this appear strange if the reader considers the bad disposition and smallness of the place, it being one of the loftiest crags of a rocky mountain, one hundred toises above the highest part of the desert of Pichincha. Such was the situation of our mansion, which, like all the other adjacent parts, soon became covered with ice and snow. The ascent up this stupendous rock, from the base, or the place where the mules could come to our habitation, was so craggy as only to be climbed on foot, and to perform it cost us four hours’ continual labour and pain, from the violent efforts of the body, and the subtilty of the air—the latter being such as to render respiration difficult. It was my misfortune, when I climbed something above half-way, to be so overcome that I fell down, and remained a long time without sense or motion, and, I was told, with all the appearances of death in my face. Nor was I able to proceed after coming to myself, but was obliged to return to the foot of the rock, where our servants and instruments remained. The next day I renewed the attempt of climbing the rock, though probably I should have had no better success than before, had not some Indians assisted me in the most steep and difficult places.”