Palmieri regarded the eruption as the last phase of a series of disturbances which began at the end of January, 1871. From November, 1868, until the end of December, 1870, the mountain had been almost quiet. Only a few fumaroles discharging smoke bore witness to the need for watchfulness. "Early in 1871 the delicate instruments of the observatory which register earth tremors were observed to be slightly agitated, and the crater discharged a few incandescent projectiles, detonating at the same time, but not remarkably. On the 13th of January an aperture appeared on the northern edge of the upper plain of the Vesuvian cone; at first a little lava issued from it, then a small cone arose which threw out incandescent projectiles and much smoke of a reddish colour, whilst the central crater continued to detonate more loudly and frequently. The lava flow continued to increase until the beginning of March, without extending much beyond the base of the cone, although it had great mobility. In March the little cone appeared not only to subside but even partly to give way, as almost always happens with eccentric cones when their activity is at an end.... A little smoke issued from the small crater, and a loud hissing from the interior was audible. By lying along the edge I could see a cavity of cylindrical form about ten metres deep.... The bottom of the crater was level, but in the centre a small cone of about two metres had formed, pointed in such a manner that it possessed but a very narrow opening at the apex, from which smoke issued with a hissing sound, and from which were spurted a few very small incandescent stones and scoriæ. This little cone increased in size as well as in activity until it filled the crater and rose four or five metres above the brim. New and more abundant lavas appeared near the base of this cone, and pouring continually into the 'Atrio del Cavallo' rushed into the 'Fossa della Vetrana' in the direction of the observatory, and towards the Crocella, where they accumulated to such an extent as to cover the hillside for a distance of about three hundred metres.... For many months the lava descended from the cone and traversed the 'Atrio del Cavallo.'... On the 3rd and 4th of November a copious and splendid stream coursed down the principal cone on its western side, but was soon exhausted. The new small cone appeared again at rest, but did not cease to emit smoke...."