The Eruption of Vesuvius in April 1906

Abstract

After the great, eruption of April 26th, 1872, the exhausted volcano lapsed into comparative repose for three years, a repose marked by merely solfataric phenomena, to awaken again in 1875, however, to a state of strombolian activity, which continued until the beginning of this present month of April, punctuated now and then by phases of lateral outpourings of lava, such as those of the years 1885,1889, 1891, 1895, etc. In the course of these the great cone was fissured, and there flowed from the fissures month after month and year after year, piling up on itself, a lava mostly of the Pahoehoe type, dense and pasty, that is, insufficiently saturated with steam and superheated water. Meanwhile, however, the quantity of this water was slowly increasing within the subterranean furnace, as was proved by the great outbursts from the principal crater, which took place in May 1900 and September 1904. As the amount of this steam and the degree of its tension continued to increase, on May 27th, 1905, fissures were rent in the north-north-western wall of the cone, whence rivulets of lava began to pour forth, from an altitude of about 3600 feet. This went on until the beginning of the present month of April, the new lava finding its way down the little valley which runs between the two hills of lava heaped up by the eruptions of 1891 and 1895, and flowing also westward in such wise as to cut the electric railway along that portion of the