ANIMAL KINGDOM. Birds. BIRDS Compose the second class of the first sub-kingdom of animals. As in the suck-givers, their blood is warmer than the element in which they live, and has a double circulation. They differ from them, however, in having it oxygenized not only in the lungs but in the arteries and veins. The bones, muscles, and other parts through which it passes are furnished with air-cells communicating with each other, and with the lungs. These air-cells tend to make the bird very light, and thus adapt it for supporting and moving itself in the atmosphere. The lungs do not hang loosely in the chest, as in the suck-givers, but are fastened to the ribs. Birds have no teeth, and cannot, therefore, masticate their food, even though it consist of grain only. How, then, is this food reduced to a soft or pulpy state? Graineating birds are furnished with an organ called the gizzard, one of the most curious structures in the whole animal economy. It consists of four distinct muscles, lined with a very callous skin which sometimes becomes horny. By their alternate action these muscles produce two effects; the one a constant friction and the other a pressure, on the contents of the cavity. These muscles are so hard and powerful that they can blunt and break needles, lancets, and other hard and pointed substances, without receiving any injury. Many of the grain-eaters assist the action of the gizzard upon the food by swallowing small pebbles, which, in some measure, serve the purpose of teeth; and some tribes cannot digest their food without this aid. Like the suck-givers, again, birds have four limbs and 1. Vide Root. To illustrate this lesson, a bird's wing, skeleton of a goose's wing, pair of web feet, feathers, &c., might be exhibited. five senses. But the anterior pair of limbs are adapted for acting against the air only, and the senses of hearing and feeling are not nearly so perfect as those of seeing and smelling. The young are produced from eggs, and are never suckled. 1 1 The eye of birds is so constructed as to enable them to see objects both far and near with equal clearness. Besides the two ordinary eyelids there is always a third, situate at the inner angle, and which, by means of a beautiful muscular apparatus, can be drawn over the eye like a curtain. The 'cornea is very 'convex, but the 1 crystalline humour is flat, and the vitreous humour small. The feathers are cast usually twice in the year, though there are numerous exceptions to this, as the hawks and larger gulls retain their nestling feathers till the second autumn, while others, as the crows and starlings, renew every feather previously to the first winter; and there are some groups, as the thrushes and wagtails, which change their first clothing plumage soon after quitting the nest, but retain their nestling primary feathers until the second autumn. This casting or changing of feathers is called moulting. The principal instinctive power of birds is exhibited in the construction of their nests, and the tender care they take of their eggs and young. Their rapid passage through different regions of the air, and the intense and continued action of that element upon them, enable them to 'anticipate the changes of the atmosphere to an extent of which we can have no idea, and which have caused them from the most ancient times, to be regarded by superstitious persons as having a power of announcing future. events. Bones of the wing cylindrical. Strength obtained by the arch form and tie. like bone or stretcher of the wing. Adaptation of each kind of foot to its purposes. Beautiful arrangement of the filaments of the feathers, the parts, and their uses in rising, in flight, and alighting. FRANCE. Successive Kings to Louis the Fifteenth. AFTER Charles the Fat, Hugh Capet, and the other kings, there were many sovereigns, but we have not space even to enumerate them. Philip the Fair began to reign in 1285. He was so called on account of his personal beauty. For the next hundred and fifty years a continued struggle was going on betwixt the French and English. Louis the Eleventh became king in 1461. He was a crafty, treacherous, and cruel king. One of the most famous of the French kings was Francis the First, who ascended the throne in 1515. He fought against the Swiss, and against the emperor of Germany; but the emperor took him prisoner at the battle of Pavia. In 1560, Charles the Ninth became king of France. He was then a boy of ten years old. His reign was disgraced by one of the bloodiest scenes in history. It is called the Massacre of St. Bartholomew. 2 The Catholics (those who were attached to the pope of Rome) had conspired to murder all the Protestants throughout France. On the night of Saint Bartholomew's day, their wicked project was put in execution. Some writers affirm that a hundred thousand Protestants were murdered. Charles died in 1574. The next king but one was Henry the Fourth, who ascended the throne in 1589. He was a good king, a brave warrior, and a generous man. His subjects loved him, and the French have always been proud of Henry the Fourth. Yet the affection of his people could not save his life. One day he was riding through the streets of Paris in his coach. Seven courtiers were with him. Other vehicles 1. Vide Root. 2. Because it was on the night of the day dedicated to that Saint, August 24th, 1572. were in the way, so that the coachman was compelled to stop the horses. The king chose to alight. There was a man near the coach, named Ravaillac. He was waiting for a chance to kill the king; and now, seeing him about to get out of the coach, he drew a poniard, and stabbed him to the heart, The murdered Henry was succeeded by his son, Louis the Thirteenth. The government was chiefly directed by Cardinal Richelieu, an ambitious priest. The next king was Louis the Fourteenth, whom the French call Louis the Great. He was a very proud and haughty monarch. This king began to reign at five years old, and reigned no less than seventy-two years. He was continually at In the early part of his reign, his armies achieved many splendid victories. war. But, in the king's old age, the English duke of Marlborough wasted his troops, and reduced his kingdom to great distress. The French people now grew weary their grand monarch. of At last, in 1715, the old king died. He was succeeded by his great-grandson, a child of five years old, who now became Louis the Fifteenth, and the Duke of Orleans, a profligate man, was declared regent. Louis XV. turned out just such a king as might have been expected. In his whole reign of fifty-nine years, he seems to have thought of nothing but his own selfish pleasures. The reign of this 'odious monarch prepared the French to hate the very name of monarchy. He died in 1774, and was succeeded by his grandson, Louis the Sixteenth, who was then a young man of twenty. GEOGRAPHICAL.-How are the following cities situated,-Paris, Lyons, Marseilles, Bordeaux, Rouen, Versailles, Toulouse, Amiens, Nantes, and Strasburg? Write the names of the principal mountains, canals, and islands. CHRONOLOGICAL.-Peter the hermit, of Amiens, heads the first crusade, 1096. PNEUMATICS AND HYDRAULICS. THE 'operations of the pump depend upon the pressure of the atmosphere. You will perceive by the engraving that it is a hollow cylinder, with a thing like a bucket in the upper part, to which the rod is attached, and another towards the bottom. These buckets are called pistons, and the upper one the sucker, or sucking piston. Both these pistons are hollow, and each has a 1valve or lid on the top, see fig. A, which is an enlarged view of the piston with its valve. When shut, these valves fit close to the hollow of the piston, so as perfectly to shut out the air. But they are fixed on hinges, which move very easily, and give way to a very light pressure. Both open upwards, towards the top of the pump. The lower piston or plug is fixed, the upper one moves up and down. When the barrel of the pump is empty, the space between the buckets is filled with air. When the upper bucket is forced down by the rod, the air between the buckets will press down the valve of the lower bucket, and shut it. At the same time, its upward pressure will open the valve of the upper bucket, through which a portion of the air will escape. When this bucket begins to ascend, the valve will fall and close the piston, and prevent the air entering the pump from above. As it ascends, an empty space, or vacuum, will be left in the pump, which the 1external air pressing on the water of the well will endeavour to rush in to fill. As the lower valve also opens upwards, it will yield to the pressure from 1. Vide Root. 2. Sucker, the term is improper, but it is used to distinguish this kind of pump from the forcing pump, in which the upper piston is solid, having no valve. 3. Liquid, any thing dissolved or melted. Fluids are permanently so, and are opposed to solids. than 32 feet for this reason. 4. The common pump cannot raise water more |