and a disgrace to the age. The poor birds are attacked at their breeding-grounds, and hundreds are slain in a few hours by single parties, whose only use of them is to secure the beautiful plumes with which Nature has unfortunately adorned them. In this way colony after colony is broken up, the greater part of the birds being actually killed on the spot, often leaving nestlings to suffer a lingering death by starvation. The few old birds that survive usually abandon the locality where for generations their progenitors had lived and reared their young undisturbed, only to be attacked at some new point the following year. The habit most of the species of herons have of breeding together in communities renders their destruction during nesting-time an easy matter, their strong parental affection leading them to be neglectful of their own safety when their young are in danger. Disgraceful and inhuman as the act may seem, many a heronry of the qua-bird, or night-heron, is annually destroyed in mere wantonness, in order that the perpetrator may boast of the 'cart-load' of birds he shot in a single day!"
The Plasticity of Ice.—Experiments made in 1871 by Prof. Bianconi, of Bologna, showed that slow changes of form in ice may be produced without any crushing or regelation, and that ice is, to a certain extent, plastic. He has lately published the results of further experiments on this subject, a brief notice of which is given in Nature as follows: "Granite pebbles and iron plates are slowly pressed into ice at the same temperatures, and not only do they penetrate into it as they would penetrate into a fluid or semi-fluid, but also the particles of ice are laterally repulsed from beneath the intruding body, and form around it a rising fringe. Moreover, when a flat piece of iron is pressed into the ice, the fringe rising around it expands laterally upon the borders of the piece, and tends thus, as in fluids, to fill up the cavity made by the body driven in. These experiments tend greatly to illustrate the plasticity of ice, but it would be very desirable that some measurements should be given, so as to obtain numerical values of the plasticity of ice under various circumstances."
Perils of Arctic Exploration.—Lieutenant Payer, one of the commanders of the Austrian Polar Expedition of 1872-'74, in his published narrative gives a graphic account of the perilous situation in which the expedition found itself on Sunday, October 13, 1872. "In the morning of that day," he writes, "as we sat at breakfast, our floe burst across immediately under the ship. Rushing on deck, we discovered that we were surrounded and squeezed by the ice; the after-part of the ship was already nipped and pressed, and the rudder, which was the first to encounter its assault, shook and groaned; but, as its great weight did not admit of its being shipped, we were content to lash it firmly. We next sprang on the ice, the tossing, tremulous motion of which literally filled the air with noises as of shrieks and howls, and we quietly got on board all the materials which were lying on the floe, and bound the fissures of the ice hastily together by ice-anchors and cables, filling them up with snow, in the hope that frost would complete our work, though we felt that a single heave might shatter our labors. . . . Mountains threateningly reared themselves from out the level fields of ice, and the low groan which issued from its depths grew into a deep, rumbling sound, and at last rose into a furious howl as of myriads of voices. Noise and confusion reigned supreme, and step by step destruction drew nigh in the crashing together of the fields of ice. Our floe was now crushed, and its blocks, piled up into mountains, drove hither and thither. Here they towered fathoms high above the ship; there masses of ice fell down as into an abyss under the ship, to be ingulfed in the rushing waters, so that the quantity of ice beneath the ship was continually increased, and at last it began to raise her quite above the level of the sea."
The Coal and Iron Resources of Alabama.—The coal and iron resources of Alabama were the subject of a recent interesting communication by Mr. William Gesner to the Academy of Natural Sciences of Philadelphia. According to the author, the coal-measures of the Warrior and Cahawba coal-fields consist severally of 172 and 173 strata. The coal-seams, which range from