Page:Popular Science Monthly Volume 16.djvu/717

Rh This sort of thing does not often occur in England, and, when it does, it lasts but a few hours at the outside; but, in certain latitudes, the requisite meteorological conditions sometimes continue for days and even weeks together, and then the results are most disastrous. The rain continues to fall, and to freeze as it falls; and the crust of ice grows thicker and thicker, until tall trees and miles of telegraph wire are broken down by the enormous weight. Fortunately, the phenomenon is generally arrested before it attains this extreme degree of development, and, when it does occur, seems to be almost entirely confined to the steppes of Southern Russia.

It may be remembered that, during the winter of 1876-'77, frequent references were made in the newspapers to the state of the South Russian telegraph lines, many of which, especially those in the governments of Kherson and Taurida, were rendered perfectly useless for weeks by just such an accumulation of ice as we have been describing. A German gentleman, Herr Bernhard Bajohr, happened to be journeying from Nicolajew to Berislaw about the middle of December, when things were at their worst; and as the phenomena are seldom seen so fully developed, even in Russia, as they were at that time, it may be worth while to give some account of what he saw. His road lay between two telegraph lines; one the Indo-European, the other that of the Russian government, so that he had ample opportunity of observing and comparing the different effects produced upon the two. But, before describing these, we must say something as to the meteorological conditions required for the formation of this peculiar ice-incrustation.

In long-continued and severe frost, the earth is frequently chilled to a considerable depth, and to such a degree that it absorbs the warmth from the lowermost stratum of air, which becomes icily cold in consequence; while the trees, buildings, etc., within the cold stratum naturally share the surrounding temperature. This cold stratum may be from twenty to forty feet in thickness, while the air above is many degrees warmer. If rain fall from these warmer regions, though there will not be time for it to freeze during its short passage through the colder air, yet, directly it touches the ground or any other ice-cold substance, it will congeal and cover it, whatever it be, with a glaze of transparent ice, as noticed above. Herr Bajohr observed that, when the ice first began to form upon the telegraph wire, it was in the shape of a cylindrical roll, which instead of hanging from the wire, or being crystallized round it, as one would have expected, merely rested upon it, the wire touching its lower circumference only. As rain continued to fall, the cylinder increased in size, until its diameter measured from half an inch to three inches. This was the first stage of development; but then the intensity of the cold abated somewhat, and the rain which was still falling, instead of freezing the moment it touched the roll of ice, had time to trickle over it, and form long rows of icicles,