That this theory is open to objection on the simple ground of probability, it does not require scientific knowledge to perceive. In the first place an eruption of Ararat is unknown within the historical period; in the second, the destruction of Akhury was only one of many catastrophes which were occasioned by earth movements on the same day. On that same evening the valley of the Araxes was visited by a violent earthquake, and thousands of houses were overthrown. [101] It is true that Wagner supposes an eruption of steam rather than of fire, and favours the hypothesis of vast reservoirs of water beneath the mountain having burst in upon the molten mass below. But this ingenious supposition is rendered unnecessary and improbable by the minute researches of the next trained worker in the same field. Abich asks how it would be possible for eruptive action to have broken forth in a narrow valley--on such a scale that huge crags of 100 to 150 feet in circumference were propelled for a distance of over three miles [102]--without leaving any trace of volcanic ejectamenta on the adjoining heights and on the slopes beyond. A careful examination of the disposition and character of the débris, as they were disclosed within the trough of the chasm, as well as on the surface of the base of the mountain, established in his mind the veracity in all essentials of the official version of the Russian Major of Engineers. He observed that the fragments of rock which are strewn over the basal slopes before the entrance to the chasm is reached, become concentrated as you proceed, and are collected into long ridges of boulders, which issue from the mouth of the gulf. Yet not a single one among these fragments was found to be identical in nature with the fragments on the adjacent valley sides. How account for this striking circumstance on the hypothesis of an eruption from fissures along the base of the valley? When he came to investigate the origin of these piled-up boulders, he discovered that they exactly corresponded with the rock of the seams which are found along the upper end of the chasm, overhanging the abyss. He was even able to ascribe approximately the former position of the largest of the crags which recline upon the base to a site on the left wall of the chasm, immediately beneath and supporting the snows. From his writings we may extract the following explanation of the phenomena to which the destruction of Akhury was due. The upper structure of Ararat had been seriously weakened on the north-eastern side by the slow but persistent action of snow and ice, and by the corrosive tendencies of veins of sulphurate of iron. The earthquake precipitated portions of the higher seams into the chasm, together with masses of snow. A dense cloud of dust was induced by the falling rocks, and the setting sun lent to this cloud a lurid hue. Immense quantities of boulders were hurried down the trough of the chasm, accompanied by a stream of mud and melting ice. The