 Chapter 34 of the Ocean of Air Meteorology for Beginners. This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. The Ocean of Air Meteorology for Beginners by Agnes G. Byrne Chapter 34 Living Dust of the Air Among the dust specks which fill the air are other minute things, not strictly dust, smaller for than the modes which we can see, invisible except under a microscope, and altogether different from mere dust, because they have in them the gift of life. These make their home in the atmosphere, floating everywhere, mingling with the air particles in countless multitudes. It has been stated that with every single breath, a man breezes he may draw, scores or even hundreds of them into his lungs, yet they are so minute that they do not put him to inconvenience. Many of these living germs of the air, infinitesimal rod-shaped forms of vegetable life, are less than the hundred-thousandth of an inch in length. They are, however, exceedingly active and frightfully prolific. One of the bacteria has been said to increase in the course of 24 hours to over 16 millions. Some kinds grow by rapid dividing and subdividing, each rod-like thing becoming two, which two divide each into other two and so on. Others increase by means of spores, as spores they can endure wide variations of cold and heat. They may even become perfectly dry like dust, seemingly dead, yet afterward they will revive. This constitutes a danger to mankind, for air abounds in such germs and spores, and water is perhaps fuller still. They are germs of putrefaction often, germs of disease sometimes. If any vegetable or animal food is left within touch of air or water, wandering germs will speedily seize upon it, feed upon it, turn it bad as we say. Food to be saved for any length of time from these destroying multitudes must be shut off from the touch of water or air hermetically sealed in a dry vacuum. But men cannot be so guarded from wandering germs of disease. It is extraordinary how long such germs, or at least the spores of them, will keep their vitality. In the olden days of plague visitation, closets from a plague-stricken district were sometimes buried for months, even for years, and when disentombed, infection broke out anew. Scarlet fever germs, diphtheria germs, may be conveyed from one person to another through dress or books or contact, or they may simply float to and fro in the air, waiting to find a victim. Some allusion has been made earlier to the dangers of great masses of decaying vegetation. The miasma or malaria of marshy lands is only too well known to travelers. Much mystery still hangs about the matter, that a close connection does exist between marshlands and certain diseases in warm climates is undeniable, while the exact nature of the connection is not so clearly understood. Dyeing vegetation gives off certain gases, including carbonic acid gas, but though the latter may suffocate a man, it does not bring on intermittent fever nor do any of its companion gases, released at the same time. The miasma poured forth by decomposing vegetable matter are minute living disease germs, which carried by the air, fasten on human beings and lay them low. A certain amount of heat and of moisture are generally counted needful for the development of the poison, yet sometimes it is poured forth from underground dampness through cracks in a dry and hardened earth. If no cracks exist, the miasma are imprisoned by the hard crust. Again, if the dampness is so excessive as to cause a sheet of water over the surface of the ground, the water acts as a guard preventing the escape of the germs. These germs of disease, when free, we are told, may be carried on the pollen of marsh flowers or on cryptochemic dust along the valleys or up the mountain sides, just as ordinary dust drifts into places here and there, leaving other parts free, so does the disease laden dust, settle in favorable spots. And again, in the vapors of the night, in the do's of the morning, the germs of the disease maintain their vitality, and in the sultry breeze may be disseminated far and wide. They are seldom known to ascend above 1500 or 2000 feet, and their spread is checked in a remarkable manner by trees, or indeed by any substantial obstacle. Obviously they do not invade large cities, but to this rule there are exceptions. The Campania di Roma is famous for its terrible malaria. Evil vapors arise from the ground, especially near the lake of Sol Fatter, and in the heights of summer malignant fevers are so rife as to make the whole Campania a dangerous place of residence. Many of the country peoples then flee to Rome, though that city does not escape occasional visitations of malaria fever. Probably the destruction of surrounding woods has made matters far worse than some centuries ago. Travellers in Malaria's district should never leave their houses till the morning fogs have melted away, or stay out of doors when the evening mists begin to form. Many an Englishman, impatient of restraint, and unbelieving as to the need for care, has fallen a victim to the neglect of this simple rule. Thus we see that the air, which brings us so many good things, brings us sometimes bad things also. There can never in this world be a power for good, which is not also a possible power for evil. That which tells one way beneficially will always tell the other way hurtfully. When a gentle old lady, recommending her pet medicine to all her friends says, It may do you good and it can't do you harm. We know that she is declaring an impossibility. That which cannot do harm, if such a thing exists, is of necessity no less incapable of doing good. Air carries injurious dust, noxious gaseous, germs of putrefaction and disease. This is true. Yet mainly on the whole, those things which the air bears upon its broad wings are for the benefit of living creatures. If we willfully place ourselves in the path of evil things, they will be brought to us. But if we take reasonable precautions, if we give the air liberty to act, they will as the rule be borne away. There is no purifying power like that of the three wild breezes. Shut up on stagnant air is another matter. A common dust mode remains for years even from centuries the same. It may stick to some other body or become detached from it. But in itself it does not change. It cannot grow. It never gives birth to another dust mode. It has not the mysterious gift of life. And the living never springs from the not living. We have around us a world of life, also a world of lifelessness. The two are utterly divided, absolutely apart. That which has not life cannot give birth to that which has life. For a long while, this was doubted. Time after time, vegetable substance was hermetically sealed in a vessel, which was then so heated as to kill, it was supposed, every kind of living thing within. Yet, weeks later, when the vessel was opened, living germs were there. So it was concluded they must have somehow sprung to life from unliving matter. But now we know that these tiny air and water germs will live through enormously greater heat than was once believed possible. The germs found alive when the vessel was opened were simply the descendants of earlier germs not killed by the heat. Closed vessels containing a vegetable solution have since been subjected to greatly increased heat. And when, after a while, they were opened, no living things were within. All the germs had been killed, and so no fresh forms had sprung into existence. There is a wonderful demarcation between vegetables and animals. Yet the two worlds of vegetable life and animal life have each a gentle slope leading down to the margin of the other. On the margin creatures are found, which may equally well belong to either side. No such gradual slope, no such doubtful belt, appears to divide the world of life from the world of lifelessness. A sheer gulf separates the two. That which has life gives birth to that which has life, but the living never springs from the not living. However low and small, however wanting in organs and powers, certain life things, such as the germs of the air, may be. They are cut off by an impossible chasm from the world of inanimate matter, the world of rock, stone and metal, of water and of air. True, the not living materials pass into and out of the bodies of the living. True, air and water, carbon and oxygen, have a share in the building up of living structures. True, men and beasts are literally made of dust and water, so far as the physical frame is concerned. Dust though art and unto dust shall though return, was no mere figure of speech as uttered unto man. But life is not in the dust, not in water, not in air. Man is largely made of carbon, and a diamond is formed of the same. Yet in the one we have the presence of life, the command of a controlling will, the ever present joy or pain of consciousness. In the other we find no life, no will, no consciousness. None can bridge the gulf between the two. None can breeze the breath of life into lifeless matter, save he who is the life. End of chapter 34 Chapter 35 of The Ocean of Air Meteorology for Beginners This is a LibriVox recording. All LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. The Ocean of Air Meteorology for Beginners by Agnes G. Byrne Chapter 35 Insects of the Air From countless myriads of invisible germs, floating and multiplying in air and water, we pass upward to higher and more complex beings, the winged insects of the atmosphere. The Ocean of Air is an ocean of life, teeming with creatures that breathe and move. These are of all kinds, grade by grade, from the lowest microscopic organisms. They arise in a steady progression, through creeping and fluttering things innumerable, till higher stages are reached. The insects of the air, multitudinous forms of life are concluded in this term. Insect is a word often used loosely, often wrongly applied. Spiders are commonly called insects, yet really they are nothing of the kind. The same mistake is made about woodlice, centipedes and other creatures. A true insect, among diverse characteristics, must always be divided into three parts, the head being so far separate as to move independently of the body. It must also have six legs and two antennae or feelers. It must breathe by means of air tubes instead of lungs. It must pass through a succession of changes, leading on to the perfect winged state. A spider has eight legs instead of six, so it cannot be an insect. Also, if you examine a fly and a spider, you will see at once how freely the fly can turn and twist his little head about, while the spider's head is part of his body. The breathing tubes of insects are very curious. They are made of an exceedingly thin membrane of skin, and they are kept in shape, always open for the passage of air, by a kind of stiff thread, like very fine wire, wound in closed spirals within the tubes throughout the whole length. These tubes parade every part of an insect's body, even the legs and feet. The smaller tubes run into bigger ones, and the biggest lead to little openings or holes in the sides of the insect, through which air passes in and out. Insects can no more live without plenty of oxygen than men can. To give in a single chapter any full details of the enormous hosts of winged insects, which strong the ocean of air, is a simple impossibility. Their names alone in a dry monotonous list would far overflow the space I have to spare. The tubes might be filled with short descriptions of British varieties, letting alone those of foreign lands. But to see the insect in its full power and beauty, as well as in its full unpleasantness, one must journey towards the tropics. The mosquito misery is pretty well known to all travelers in South Europe at certain seasons of the year, as well as to all developers within the tropics. Although Indians are apt to wax eloquent describing past wakeful nights, vain hunts after vanishing foe, frantic endurance of a shrill, unquenchable buzz, and spotted swollen faces for many a day following. Yet the mosquitoes have their use. Devouring travelers is not the normal occupation of the mosquito. Food note. Yee-Jee Wood. The greater number of facts in this chapter are cooled from his delightful insect volumes. End of food note. It is merely a little passing entertainment, belonging to its last and highest stage of existence. Before becoming a perfect insect, the mosquito dwells under water as a grub or larvae, and there it feeds vigorously upon minute specks of decaying substance, thus helping to render the water pure. Of all insect pests, none is greater than that of the locust, a creature seldom met with in England. Some few locusts appear perhaps every year, but many reported as such are really some other insect, mistaken for the distinguished foreigner. In hotter lands, the migratory locust is a fearful scourge. When once the warning signs are noted of the coming peril, no human power can avert it. Nothing but the change of wind is of any avail. Where the air currents flow, there's the locust go, helplessly, and as if without will of steerage power. Countless hordes of brown creatures darken the atmosphere. Opposition seems useless, for nothing turns them aside. Brushwood over-avide track is set blazing, and still the mighty swarm sweeps by, myriads upon myriads dying in the flames. While yet the army as a whole seems undiminished. I have spoken of their advent as a peril, and so indeed it is. Not directly, but indirectly, a peril to human life. For when once the locust army settles, the country around is doomed. Grain, fruit, vegetables, leaves, flowers, all are ruthlessly devoured. A visitation of locusts in the east means a famine to fellow. Still die for lack of food, so meat as well as corn and vegetables fail. Parts of southern Europe have often suffered from locusts, but it is in Asia and Africa that they are seen in fullest force. One vast array of Indian locusts extended in length to no less than five hundred miles, and as the swarm flew by, the air was so darkened that big buildings only two hundred yards off were almost blotted out. Other insect plagues might be mentioned also. There is the fly torment of a hot summer and of tropical climates. There are wasp torments, cockroach torments, spider torments, they worry and distress the human beings of almost any kind of superabounding insect. More serious pests than these exist in such creatures as the famous Zetze fly of Africa, which exterminates with its deadly sting all large quadrupeds throughout the district where it lives. If ever Zetze makes its way to British source and finds British air to agree with its constitution, then goodbye to our flocks of sheep, our herds of cattle, our fine breeds of horses. Not one of them could stand against the Zetze. Among the fairer and more innocent creatures which float through the blue depths over our heads, the short-lived mayfly is perhaps one of the most abundant. As a perfect insect it lasts commonly but a few hours. Since no food is needed for so short an existence it has no mouth. The brief span is passed in a merry, though monotonous dance upon the summer air. In some parts of Europe mayflies have multiplied to such an enormous extent that their little dead bodies have been gathered into piles and used for manure. Dragonflies, often called horse-tingers, are most harmless creatures so far as quadrupeds and men are concerned. The ideas that they possess stings is a popular delusion. The long, quivering bodies are powerless to do an injury, and if they could bite they do not. No doubt in the insect world a different tale would be told, for the dragonfly is a ferocious wild beast, a veritable dragon there. In all the different stages of its existence he is voracious to a degree, and in the latest full-blown stage he is as ready to make a meal of spiders and centipedes as of smaller insects. One African dragonfly is bright red in color, with brilliant, opal-hued eyes. Another, a native of India, has brown upper wings, the other two being of vivid metallic green. Again, a dragonfly of Borneo possesses wings crimson blue and green, according to the lights in which they are viewed. Even in England we have a kind, the wings of which glitter, with iridescent hues of metallic purple, green, blue and gold. It is a pity that all these radiant colors fade after death. Many insects are helpless in a strong breeze, but the powerful wings of the dragonfly, beating the elastic air, are equal to this emergency. Like a vigorous rower, delighting to make way against a rapid stream, the dragonfly seems to rejoice in mastering the wind. A remarkable piece of mechanism exists in the wing of the dragonfly. We all understand how a rower makes his way. With the stroke that sends him forward, he presents the breath of his oar to the water, so as to have a strong pull against it. Then instantly he feathers his oar, letting the water resistance act only on the edge of the blade. But with the vigorous strokes of a dragonfly's wing, how is it that the upward stroke does not exactly neutralize the downward stroke, so as to keep the insect just moving to enthrow in one place? Simply because they are not mere up-and-down strokes. By a wonderfully delicate mechanical arrangement, a kind of little muscular spring, the wings are feathered with every upward stroke. The down stroke makes full use of air resistance, to send the insect darting forward, but in the up stroke, the edge of the wing slips through the air, meeting with slight opposition. Insects in general do not merely float on the air like balloons, through excessive lightness. Most of them are so light and weak, that the breeze sweeps them away. Yet each has its own weight, and each, in perfectly still air, would sink to the earth, but force a rowing action of its wings. A common housefly beats the air about six hundred times each minute, thus making a continuous humming sound. Without some degree of weight, there cannot be real flight. The helplessness of locusts in their migrations has been mentioned earlier. They do not fly like dragonflies against the wind, but are swept along by it. Locusts generally are not good for much in the way of light. When about to depart on a long aerial journey, they make preparation by blowing themselves full of air—footnote—from Professor Duncan's transformation of insects, end of footnote. So full, that the airtubes of their bodies generally flat bulge out and become rounded. This makes them lighter than usual to begin with. Then the exertion of flying heats their bodies, and the air in the airtubes grows warmer, therefore lighter. The locust thus really does float partly, through lightness as used wrongly to be supposed of all flying creatures. But the very fact that it does so makes it to some extent like a balloon—the mere sport of the winds. We have in England some insects which can fairly compete in appearance with their brethren of foreign lands, but it is not so with butterflies. Think what our world would be without flowers or butterflies, without fair ornaments of the earth and of the air-ocean. Often unlovely insects help to purify the physical atmosphere, but beautiful things, such as flowers and butterflies, help to soften and purify the mental atmosphere, is one more needful than the other. Butterflies in countless varieties are known to us, from the tiny blue things coming over English meadows, to its splendid cousin of the Himalayas, with radiant-tailed wings peacock marked in shaded blue and green. One exquisite native of tropical America, we are told, seems to partake with the gems the full glory of color. It is scarcely possible to conceive of a living creature that can surpass this insect in absolute magnificence. The upper surface is radiant as sure as if composed of a sheet of thin mother-of-pearl. When the light falls in the right direction, the color is so intense that the eye can scarcely endure its radiance. And again of another we learn, the upper surface of this butterfly is rich-shining opaline blue with a decided dash of green in some lights. The wings are edged with a broad band of black in which is a row of little white spots. Another fine creature found in South America is known as the owl butterfly. It is very large in size, the wings being on the outside a chocolate brown, shot with blue and green. The curious part of this butterfly is the under-view, there, when the wings are well opened, a distinct and remarkable picture of an owl's face is seen. The general surface is done colored with brown motlings, in the center of each lower wing is a painted eye, and the body of the butterfly serves perfectly for a beak. A preserved specimen of this creature is, or was recently to be seen at the Crystal Palace. I can vouch after sight for the striking resemblance to the face of an owl. The dead leaf butterfly is a no less singular instance of imitation in form, so often seen among insects. This kind belongs to the Himalayas, though found elsewhere also. When open and in the act of flight, there is nothing unusual about it, but when the wings are closed and the animal is still, there is every appearance of a dead leaf, brown and veined. A dried specimen in a glass case, sent home years ago from India, has drawn often the remark from a passing observer, why you've got a dead leaf in there. A very different kind of insect from the butterfly displays the same tendency to imitation in appearance, I mean the walking stick insect. Some creatures of this kind are the most complete copies of dried sticks, and certainly are more curious than beautiful. They are among the largest known insects. One variety is as big round as a man's thumb, and when its legs are outstretched it is 15 inches long. Another, found in New Guinea, has hind legs, the thighs of which are half an inch thick and over an inch and a half long, while its eggs rival those of a hummingbird in size. It has big scratching body thorns or spikes and sharp leg prickles. On the whole, one would prefer not to come across any such monster insects in our English woods or meadows. End of chapter 35. Chapter 36 of the Ocean of Air, Meteorology for Beginners. This is a LibriVox recording, all LibriVox recordings are in the public domain. For more information or to volunteer, please visit LibriVox.org. The Ocean of Air, Meteorology for Beginners by Agnes G. Byrne. Chapter 36, Birds of the Air. The birds of the air, how natural an expression it seems. We talk of the birds of the air involuntarily as of the fishes of the sea and the beasts of the earth. Practically as more than once stated before, all living creatures are creatures of the ocean of air. Since all breathe air, none can live without air. But the birds, living on the very wings of the wind, delighting to soar into highest regions of the atmosphere, are in the fullest sense inhabitants of the air. Birds do not merely float on the air anymore than do insects. No insect even is lighter than perfectly still air, and no bird exists which is not very much heavier than air. A balloon floats because of its lightness, and so becomes the helpless sport of the air currents. A bird can resist and struggle against the wind. True, birds are light in make. With hollow air-filled bones, if not so, each bird would need much longer wings and much stronger muscles. Then are, not necessary. But its weight is shown by the fact that if wounded and disabled when flying, it at once falls to the ground. A bird actually lighter than air would float still, even when wounded. Since it keeps itself up through active exertion, it drops when active exertion becomes impossible. When a man rows himself over a lake, he is not merely floating. The boat does float, but it does not advance by means of buoyancy. The man propels the boat by using the resistance of the water. He pushes the boat forward by pushing against the water. A bird does this and more. The bird not only rows itself forward, but also raises itself upward and keeps itself aloft by actual force. A bird's flight is a question, not of lightness, but of force against force. It uses the resistance of the air, as the rower uses the resistance of the water. No bird could fly in a vacuum, even if it could live there. The wings would have nothing to push against. Wing movement is often extraordinarily rapid. When the heavy slow harem flaps its great pinions at a rate of 130 or 40 strokes each minute, twice that if we count the upward as well as the downward motion. Small birds, particularly pheasants and partridges, vibrate their wings with such speed as to leave only a blurred impression on the eye. In other words, each flap remains upon the retina of the eye, until the next comes to mingle with it. A bird is actually forced forward by the elasticity of the air. Like water, only to a greater extent, air may be compressed. But there is always in both fluids a quick rebound or reaction. The wings of a bird striking downward compress the air sharply, and the instant expansion of that compressed air drives the wings on, sending the bird with them. For this purpose, the wings are both strong and light in make. They are also joined to the body at such an angle that each stroke necessarily sends the bird forward. A bird cannot fly backward, for the whole set of the wing and the wing feathers is against such a motion. It may drop backwards, yielding itself to the influence of gravitation, and only guiding or steadying itself by wing movement. But actually to fly backwards is an impossible feat. Nor can it rise upward except head foremost. Merely to float upwards in any sort of position is again beyond its power. The first rising from the ground implies a certain amount of vigorous exertion, which in the case of very large and heavy birds becomes an actual struggle. Once aloft and underway, they sail onward easily enough. The same difficulty which we saw wonderfully met in the case of the dragonfly recurs here. If each downward stroke of the wing forces the bird onward, how is it that each upward stroke does not undo the work of the last downward stroke, forcing the bird equally far backward? In a bird, there is no curious mechanical arrangement for feathering its feathered oars at every stroke. An answer has been given already. The set of the wings altogether is such, as to render forward motion easy, backward motion difficult. Also, a bird's wing is rounded or convex on the upper side, hollow or concave on the underside. By the downward stroke, it discloses and compresses air vigorously, while in the upward stroke, air flows over the edges and escapes all ways. Moreover, a beautiful contrivance is seen in the arrangement of the feathers. They are made so to underlap one another, that when the downward stroke takes place, the compressed air below forces them into a more compact shield, through which little or no air may pass. But when the upward stroke takes place, a precisely opposite effect is seen. The feathers then open and part asunder, and the air streams freely through. Who does not see a mighty mastermind at work, in all these wondrously delicate adjustments of nature? Who will not, if he will? Birds do not always fly, with quick and vehement wing vibration. Sometimes, seated by the sea, one might say, a gray and white seagull lying calmly on the air. Its heavy white waxen body floating apparently like a feather, with outstretched wings scarcely stirring. This is a feat in which some birds are very much more expert than others. In an absolutely still atmosphere, it would not be possible, but air, as we have found earlier, is seldom, if ever, absolutely still. The effects of wind may be produced in two ways. Either by the air flowing against motionless objects, or by objects moving through motionless air. Now, here is a practical carrying out of that principle. A bird keeps itself aloft by striking its wings against the air, so using air resistance to overcome the gravitation which drags it earthward. But suppose a wind is blowing against the bird when it is aloft. If the bird is sufficiently dexterous, it may so use the resistance of that moving air against its outspread wings, placed at a certain angle, as to overcome the attraction of earth, and yet to remain still. It is a most delicate and scientific operation, and many birds are incapable of attempting it. The kestrel, as well as the seagull, is an adept at such soaring, and so also is the mighty albatross. Those who have seen the albatross, writes the Duke of Argyle, footnote, from the reign of law, and footnote, have described themselves as never tired of watching its glorious and triumphant motion. Trunk will its spirit seemed and floated slow, even in its very motion there was rest. Rest, where there is nothing else at rest in the tremendous turmoil of its own stormy seas. Sometimes for a whole hour together, the splendid bird will sail or wheel round the ship in every possible variety of direction, without requiring to give a single stroke to its pinions. Those long, slender wings, some 15 feet across from one extreme tip to the other. Such wings are peculiarly adapted for flying long and far, for floating at ease, and for overcoming the force of ocean gales. Short-winged birds may advance fast, but they cannot keep it up long, and floating on the air at ease is out of their power. When one thinks of bird life in general, with all its infinite shades of variety, the difficulty is to know what to select for a few paragraphs on the subject. Bird kinds count by thousands and tens of thousands. Bird ways are as varied as human ways, not to say more so. Taking Britain alone, birds pass downward in gradual progression from the Great Eagle to the Little Wren, numberless multitudes lying between. Taking the world generally, the list already so long is tremendously extended. For then, the range extends from the huge, ungainly ostrich to the tiny, brilliant hummingbird. Where the more temperate climates of Earth are found, each season brings its own peculiar phase of bird life. This is markedly the case in England. Winter means commonly for birds an uncertain wandering existence. They have to be very much on the tramp in search of food, except where they find attainable stores or better still kind human friends to scatter crumbs day by day. A long and hard frost tails severely upon the birds of the air. Heavy snowstorms break through all their usual habits, slaying large numbers, driving oceanic birds inland, making shy ones tame and wild ones almost domestic. Sea gulls have been seen as high up the tames as Westminster Bridge and even the distant dignity of the eagle is not always proof against intense cold. Some years ago, when I was with friends in Scotland, we came across a worthy highland cottager living in a lonely spot not far from the D. She described a long and bitter winter in terse terms and told how the very eagles had come down from the mountain retreats to have around her cottage looking out for scraps of food. River-hunting birds whose food lies under water are among the worst off at such times. A sheet of ice means starvation to many a lovely blue and green kingfisher, sitting for lourney among the ice-clothed bushes, vainly watching the hard surface which his beak cannot penetrate. Coming spring works a wonderful change in the world of bird life. Spring is the time for all their pretty lovemaking and mating, for any amount of singing and quarrelling, for diligent nest-building and egg-laying. The roofs are hard at work and the sound of the coco is heard. While the woods and meadows ring with the wild sweet voices of thrush and blackbird, Lynette and Robin. For of course, the Robin sings still as he has bravely done all through the winter cold. Only he is now part of a general chorus, not one among a very few solos. Then too, the winter absentees begin to return. The tiny villover and still silently back from his winter retreat in Africa and the swallows and martins troupe homeward by no means silently. Some repairs are old nest and some build new ones. The nests are various in kind as the builders. Delicately finished constructions here, rough piles of sticks and moss there. Summer comes next. A time of calm happiness to birds, only broken in upon by the inevitable trials of domestic life, by strong weather, and by the attacks of the strong upon the weak. In certain other lands, little birds have been almost exterminated, but in England they still spend in the main joyous summer days and insects have not yet a chance of overwhelming the farmers for lack of birds to feed on them. Birds' voices wane as summer goes by and little families are launched in life and arrangements for autumn gradually begin to take shape. The migratory birds draw more together as if disposed to talk over their plans. Autumn is the time for change, except with those little constant birds who cling facefully to home through all, taking their chance of ice and snow and bitter blast. Both late summer and early autumn are a quiet, not to say a depressed time in the bird world. For molting takes place and singing voices have vanished and bird powers generally are at a somewhat low ebb. When molting is over, the robin gets back his voice and also do the wren, the skylark and a few others. But the autumn singing however sweet never approaches the outburst of sound which belongs to spring. Even home staying birds are very busy, seeking winter retreats and those who have a long aerial voyage ahead are in all the flurry of a speedy departure. Many people can never travel without a certain amount of preliminary fuss and birds seem to follow the same rule. After all, no wonder a perilous route lies before them. Migration of birds is beset with many dangers and difficulties. Birds often lose their way. A contrary wind or a spell of dark cloudy weather appears to disorganize their movements and like mariners without a compass, they are at a loss which direction to take. Footnot from Siddixon. End of Footnot. The wonder seems to be not that they often lose their way through the trackless depths of the air ocean but that they ever find it. How far they journey by instinct and how far the younger birds are guided by the knowledge of older ones who have traveled the same route before who shall declare with certainty. Strange sights are sometimes witnessed in an autumn evening by the men of a lighthouse. Generally, the migratory companies of birds are lied to roost and sleep as night approaches but sometimes a dark cloud shutting off the daylight with suddenness takes them by surprise and the gleams of the lighthouse lamp draws them out of their paths causing further confusion. At such a time, myriads of birds may be seen to pass, ducks and swallows, geese and wrens, finches and herons, swans and larks, these and others intermingled with birds of prey, forgetting to pray, while their usual victims forget to flee from them. All alike are bewildered, frightened, hurrying to and fro, wondering hither and thither, not knowing whether to turn. Too many dash out their brains against the strong gloss of the lighthouse and so never even make a fair start for the southern land, whether they are bound. Yet out of all the perils which they meet, great numbers do arrive safely and great numbers do come back again to us next spring for fresh singing, mating, nest building and family rearing. It has been lately asserted that no less than 90 varieties of birds may be seen in London alone, not counting escaped foreigners from cages. Rukkerees still exist there and even owls are to be found within metropolitan limits. Injectors are tolerably common. The blackbird and the thrush are not absolute strangers. Swallows fly to and throw, though they will not build in the great city. And while the red breast issues London streets, it still clings to the outskirts. The London birds par excellence are sparrows and pigeons. Before the days of electric telegraphs, the pigeon was the usual news carrier. One well-trained will fly at the rate of a mile a minute, keeping up the speed persistently for 100 miles. Marvelous as it sounds, it is exceeded by other birds. Rukk, going at full speed, beats the fastest express train ever made by man. Or he can hasten through the ocean of air at the rate of 100 miles an hour. The length of time that some birds can fly without needing to alight is extraordinary. Seagulls have been known to accompany steamers all across the Atlantic Ocean, careless of the roughest headwinds, floating about with most absolute ease and apparent absence of exertion, scarcely seeming ever to rest. They are set to sleep upon the wing, tucking away their heads like a cannery on its perch, rocked on the bosom of the wild winds, flying in sleep as we all breeze in sleep, unconsciously and mechanically. From the wide world of bird life, we might pass onward still through multitudes of small and great beasts till another wide gap is reached, that which divides brute life from human life, that which separates the most highly developed intelligence of lower animals from the wonderful brain and spirit powers of man. Even man, however, had as he is of the animal kingdom, unutterably superior to the noblest of his subjects in possibilities, if not always in action. Even he, in this life, can but creep about on or near the bottom of the aerial ocean. Even he can but watch from thence with curious eyes the wonders of that ocean, searching into its make, its movements, its governing laws, its conflicting forces, its countless forms of life. End of chapter 36. End of The Ocean of Air, Meteorology for Beginners by Agnes Giburn.